Much attention has currently been drawn toward development of new environmentally-friendly technologies for pulp and paper manufacture． As we know,pulp and paper manufacturing constitutes one of the largest industry segments in the world in term of water and energy usage and total discharges to the environment．Traditionally,paper pulps are usually produced from wood fibres using chemical and mechanical methods． Mechanical pulping characterized by its high yield，is considered as an appropriate way to extend the resources used as raw materials，but it is extremely energy-intensive．In chemical pulping，the goal is to remove lignin from wood and leave the cellulose and hemicelluloses．The primary chemical pulping process employed today is the Kraft process，in which wood chips are cooked in a solution containing sodium hydroxide and sodium sulfide．The yield from chemical processes is generally lower than mechanical pulping due to some degradation of cellulose．A second drawback to chemical pulping is the large amount of potentially hazardous chemicals which pose a threat to both mill workers and the environment．Nowadays，biopulping is being considered a suitable or complementary alternative to traditional methods due to its ability to reduce the environmental impact of paper-mill industries and to save energy and chemical costs．The process of paper-making，in essence，is the process of removing lignin．Biopulping is defined as the treatment of lignocellulosic materials with lignin-degrading fungi prior to pulping． Amongst these white rot fungi that can produce lignin peroxidase(LiP)， laccase(Lac)and manganese peroxidase(MnP)are the most proficient biodegrader．The fungus is non-sporulating and is a selective lignin degrader．It colonizes either on living or dead wood and decomposes all wood polymers including lignin and extractives making it to be extremely potential to be used in biopulping．In this study,major research work was conducted due to the disadvantages of orthodox methods mentioned above and the results are shown as follows：
　　1．One strain of white-rot fungi that can degrade lignin effectively was screened from rotten wood and barks of trees and then identified as Polyporus varius．
　　2．During 14-day liquid culture，the enzymatic activity of LiP reached 213 IU/mL，Lac 546 IU/mL and MnP 1009 IU/mL，respectively．It demonstrates that this strain has excellent enzymatic activity．
　　3．The fungus was utilized to perform biopulping and the effects of the optimal pretreatment conditions(pretreatment pH，temperature， inoculum concentration and time)on holocellulose content and kappa number in pulping by Polyporus varius using Poplar and Broussonetia papyrifera chips as paper-making materials were studied and the optimal pretreatment conditions of Broussonetia papyrifera chips by Polyporus varius were pH 5.0，temperature 39℃，inoculation of 20％，pretreatment time 15 days and poplar chips pH 5.5，temperature 39℃，inoculation of 25％，pretreatment time 16 days．Under these conditions，the lowest kappa number of Broussonetia papyrifera pulp reached 10.012，that of Poplar pulp was 14.164．The holocellulose of both poplar pulp and Broussonetia papyrifeFa pulp was decomposed by 0.005％ and 0.04％ respectively,compared with the control samples．It reveals that the optimum conditions for different paper-making raw materials are different．It can also be seen that the strain has good stability in the acidic environment．During the experiment，the holocellulo se content of both Poplar and Broussonetia papyrifeFa chips was slightly degraded by Polyporus varius with the increase of pretreatment time，but the extent of degradation was less than the kappa number．It also indicates that while lignin is decomposed，a slight degradation of holocellulose is conducted by this strain．Therefore，cellulose degradation needs more attention when papermaking raw materials are pretreated by white rot fungi．At the meantime，the microorganisms that do not depose cellulose are supposed to be screened from nature for clean biopulping．
　　4．The white rot fungus was selected to grow on both Poplar and Broussonetia papyrifera chip s and the degradation rate of lignin was investigated．The results indicate that the lignin degradation rate of Broussonetia papyrifera chips reached 23.07％ and it caused reduction of electrical energy by 19.81％ at 37℃．pH 5.0 and 10％ of inoculum concentration after treating the chips for 20 days and that of Poplar chips was 24.16％ at 37℃．pH 4.5 and 10％ of inoculum concentration and electrical energy consumption was reduced by 19.60％ during refining after treating the chips for the same time．The experiment indicates that it will be a potential lignin degrader with application in biopulping．
　　5．Biological pretreatment of wood chips prior to chemical pulping could result in reduction of chemicals by 0.5-10.3％in this work．This means the cost of chemical pulping can be reduced and the decrease of chemical consumption in chemical pulping operations will lessen the pollution level caused by effluents from paper mills．It is suggested that this new technology will certainly not only bring benefits to paper-making industry,but also make the earth a clean place．Therefore， biopulping will have great prospects in the future．