Objective： To study the clinical efficacy of electroacupuncture （EA） on treating knee osteoarthritis （KOA） of Shen （肾）-Sui （（肾） insufficiency （SSI） syndrome type. Methods： A total of 245 patients （279 knees） of KOA-SSI were randomly assigned to two groups by lottery： 141 knees in the treatment group and 138 knees in the control group. The treatment group was managed with EA at the dominant points of Neixiyan （Ex-LE4） and Waixiyan （Ex-LE5） as well as the conjugate points of Xuanzhong （GB39） and Taixi （KI3） for 30 min, once a day, with 15 days as one course; 2 courses were applied with a 5-day interval in between. The control group was treated with intra-articular injection of 2 mL hyaluronic acid into the affected joint every 7 days for 5 times in total. The clinical effects on the patients in different stages were observed, and their symptom scores of knee and contents of cytokines, including interleukin-1 （IL-1）, interleukin-6 （IL-6）, tumor necrosis factor- α （TNF- α）, prostaglandin E2, （PGE2α） and matrix metalloproteinases-3 （MMP-3）, in the knee joint fluid were measured before and after treatment. Results： The study was completed in 235 patients （263 knees）; four patients （7 knees） in the treatment group and six patients （9 knees） in the control group dropped out. Comparison of therapeutic effects （excellent and effective rates） between the two groups showed insignificant differences （P〉0.05）. Symptom scores of knee and contents of cytokines in the knee fluid after treatment were lowered significantly in the patients of stage Ⅰ -Ⅲ in both groups （P〈0.05 or P〈0.01）. However, the lowering of the total symptom score of knee in the patients of stage Ⅲ in the treatment group was more significant （P〈0.05）. Conclusions： EA could effectively alleviate the clinical symptoms in KOA patients of stage m, showing an effect superior to that of hyaluronic acid. EA also shows action in suppressing the secre
