侵犯财产类违法犯罪行为历来是我国法律打击的重点。但在实践中,小数额侵财行为时有发生,将这些游走于刑法边缘的行为认定为违法或犯罪始终存在争议。当前,《刑法》规定盗窃、抢夺等罪可以不计数额直接以多次入罪,而对多次诈骗是否入罪,数额能否累加则并未提及,形成分歧意见。文章以任某等三人诈骗案为例,从罪刑法定原则的适用、诈骗罪的特征、制裁的成本效益等方面细致分析,得出结论,认为多次小数额诈骗行为不能认定为犯罪。 Infringement of property crimes has always been the focus of our law against. However, in practice, small amounts of acts of encroachment happen from time to time. It is always controversial that these acts that go on the verge of criminal law are found to be illegal or criminal. At present, the Criminal Law stipulates that crimes such as theft and robbery can be directly criminalized on multiple occasions regardless of the amount of money involved, and whether crimes against multiple scams have been criminalized or not. This article takes Ren Mou and other three person fraud cases as examples to analyze the legal principles of crime and punishment, the characteristics of fraud crime and the cost-effectiveness of sanctions. It concludes that many times the small amount of fraud can not be identified as a crime.