In this research, we examined the biodegradation effects of three white rot fungi on cotton stalks.The results showed that three white rot fungi could degrade cotton stalk lignocellulose effectively at a certain degradation stage, the hyphal protein forming ratio had high significant negative correlation at the 0.01 level with hemicellulose and cellulose contents in biodegradation process;degradation period was determined as 15 days based on lignocellulose degrading ratios examination;taking the rule as highest lignin degrading ratio and lowest cellulose degrading ratio, Phanerochaete chrysosporium was chosen as main degradation strain of cotton stalks.FTIR results revealed that the intensity of absoption peaks of lignin, cellulose and hemicellulose decreased in 15-day degraded samples compared to original sample, especially the lignin related groups degraded strongly, which demonstrated that all the three white rot fungi degraded the cotton stalk lignin effectively.SEM results showed that hypha of white rot fungi entered inside the lignocellulose of cotton stalk, and destroyed the structure, forming many cracks and holes, which exhibited good breaking and extending capability.