Objective To study the effect of Bi Yuan Shu Liquid on melioration of clinical symptoms and signs of chronic nasal sinusitis or nasal polyp patients after Functional Endosoopic Sinus Surgery (FESS), and discuss the effectiveness of Chinese composite medicine in the overall treatment after FESS. Methods A total of 340 patients were randomly allocated to treatment group (n =170) and control group (n =170) according to simple randomization procedure. Patients in treatment group were administrated with quinolone, steroid, and Bi Yuan Shu Liquid, which were compared with those in control group who were given quinolone and steroid. Results The apparent effect of treatment group and control group were 30.6% and 42.4% of 42.4% of ITT. Results by Wilcoxon signed rank test indicated that there was a statistically significant difference. Conclusions Bi Yuan Shu Liquid may improve the effectiveness of sinus surgery, reduce the time course of antibiotics and hormones, and with out toxicity and side-effect.