This thesis aims to investigate whether Chinese and Thailand IPOs’ firms use accrualsbased and real activities-based earnings management to manipulate the net profit around the period of IPOs.China is the fastest economic growth in the world and Thailand is the emerging market country.The firms of both countries want to enter the stock market to finance the fund and making their wealth.Entrance the stock market is not simple but not too difficult.The high standards and strict criteria are required for firms to get into the stock markets.Thereby,the firms’ managers may use their power and competence to apply accounting choices or judge the structure of business transactions,to prepare and to present the financial reports to reach stock markets threshold.Managers can use different tools underlying the different socio-economy to manipulate earnings.Taking into consideration,this thesis aims to explain and to predict earnings management behaviors in IPOs’ firms between China and Thailand,both in motives and practices.The findings of the literature reviews indicate that both counties have practiced earnings management both accruals-based and real activities-based.Its motives are variously major,the categories and summaries indicate that highest motives of earnings management are the stock market motivation followed by contracting motivation and political cost motivation.However,the classification shifting-based earnings management is not found in both China and Thailand.The conclusions of the institutional background indicate that China has stricter regulations of the stock market compared to Thailand.This factor will be used as proxy of stock market motive that influence earnings management before the firms go IPOs.China has lower interest rates rather than Thailand but the effective tax rates（corporate income tax）in China are higher than Thailand.These two factors will be used the proxies of debt covenant motive and political cost motive that affect earnings management after the firms go public.Based on the result of the literature reviews and the institutional background,this thesis comprehends the theories that used to compose prior earnings management research to set hypotheses.These theories are including the efficient market theory,the agency theory,the contracting theory,and the political cost theory.Research hypotheses comprise four groups of the difference of earnings management practices,earnings management motives before and after the firms go public.Firstly,to examine that China and Thailand exhibit differences of accruals-based and real activities-based earnings management around IPOs years.Secondly,to examine the stock market incentives are positively relationship with earnings management practices of Chinese and Thai firms before they go public as well as to predict Chines firms make more incentives compared to Thai firms.Thirdly,to examine the contracting motive or debt covenant incentives are positively relationship with earnings management practices of Chinese and Thai firms subsequent initial offerings as well as to compare that debt covenant in China makes more incentives compared to Thailand.Finally,to examine that the political cost incentives are negatively relationship whit influences earnings management practices of Chinese and Thai firms subsequent initial offerings as well as to compare that the political cost in China makes more incentives compared to Thailand.The earnings management proxies that use to empirically examine the research hypotheses comprise two methods.First one is the aggregate accruals-based earnings management of the Modified Jones Model proposed by Dechow et.al.（1995）.Second one is the real activities-based earnings management developed by Roychowdhury（2006）including the Sales Manipulation Model,Over Production Model,and Discretionary Expenses Model.The sample data is collected from the CSMAR and database and the SEC of Thailand including 10 years,from 2007– 2016.Total sample data for accruals-based earnings management are 20,509 of Chinese firm-year observations and 817 of Thailand firm-year observations.Total sample data for real activities-based earnings management are 3,545 of Chinese firm-year observations and 158 of Thailand firm-year observations.The first hypothesis uses the two independent sample t tests and Wilcoxon rank-sum test.Others hypotheses use panel regressions to test and control variables.Descriptive statistic employs the distributional statistic and univariate difference for continued variables,and the proportion statistic and univariate difference for discrete variables.In addition,the Mscore model and the Z-Score model are used in the cases study.The results of case study support the thesis hypotheses which are firms in China and Thailand exhibit difference earnings management.Earnings management practices are influenced by stock market incentives before IPOs’ firms go public,and also influenced by debt covenant and political cost incentives after IPOs’ firms subsequent initial offerings.The results of comparative study indicate that the IPOs’ firms in China and Thailand exhibit difference of accruals-based and real activities-based earnings management around IPOs years.The direction of earnings management indicates that the accruals-based is prominent in Thailand.Meanwhile,real activities-based is prominent in China.The reason is the difference of institutional backgrounds such as stock market criteria,the adoption of IFRS,and the accounting regulations.These factors influence Thai managers prefer to use the accruals-based rather than the real activities-based.In contrast,these factors influence Chinese managers prefer to employ real activities-based rather than accruals-based.The results of earnings management motives before IPOs indicate that stock market incentives are positively relationship whit earnings management practices for both Chinese and Thai firms.Consider the differences of motives,the more attractive and stricter stock market criteria in China make Chinese firms have more incentives to manipulate their reported earnings compared to Thai firms.The results of earnings management motives after IPOs indicate that the debt covenant motives are a positive relationship with earnings management practices both Chinese and Thai firms,and Chinese firms have more incentives compared to Thai.Meanwhile,political cost motives are negative relationship with earnings management practices both Chinese and Thai firms,and Chinese firms have more incentives compared to Thai.Finally,the results provide evidence of earnings management incentives that Chinese firms are more linked to the stock market incentive,contractual debt costs and effective tax rate compared to Thai firms.This research contributes relevant findings and knowledge with empirical evidence to research on accruals-based and real activities-based earnings management.It has pioneered comparative research involving two countries by providing direct evidence regarding the mechanisms of accruals-based and real activities-based earnings management in IPOs’ firms in China and Thailand.The outcomes of this research can provide effective evidence for researchers or scholars and help them to understand IPO firms’ mechanism.By sharing the unique features of both countries,this study can help monitoring bodies to set regulations that are appropriate to their country’s economic conditions.