Objective To evaluate the clinical efficacy and safety of Yaotongning Capsule（ 腰痛宁胶囊

YTN）on lumbar osteoarthritis with cold-dampness and blood-stasis syndrome. Methods With the method of multi-center randomized controlled trial

totally 360 patients of lumbar osteoarthritis with cold-dampness and blood-stasis syndrome were randomly divided into YTN low-dose group（ 4 grains each time

once a day）

YTN high-dose group（ 6 grains each time

once a day）

and Bitongning Capsule group（ 2 grains each time

twice a day）. All patients were treated for 4 weeks. The visual analogue scale（ VAS） of rest and activity pain

Oswestry disability index（ ODI） before treatment

2 weeks and 4 weeks after treatment were compared. ODI efficacy was evaluated. The analgesic time of rest pain and activity pain

and adverse reactions were observed. Results After 2 and 4 weeks treatment

VAS（ rest and activity pain） and ODI score of all groups were decreased when compared with those before treatment（ P <0. 05）. The VAS（ rest and activity pain） and ODI score of YTN low-dose group and YTN high-dose group were significantly decreased in comparison to those of Bitongning Capsule group（ P < 0. 05）. The ODI excellent rate of YTN high-dose group was greater than YTN low-dose group

greater than Bitongning Capsule group

and the difference was statistically significant（ P < 0. 05）. The differences of analgesic time of rest pain and activity pain among groups were statistically significant（ P < 0. 05）

and the YTN high-dose group had the best effects. Two cases of adverse reactions appeared in YTN low-dose group

3 cases in YTN high-dose group and 2 cases in Bitongning Capsule group. There was no statistically significant difference between groups（ P > 0. 05）. Conclusions YTN can alleviate the pain of lumbar osteoarthritis with cold-dampness and blood-stasis syndrome

improve analgesic effect and the waist function.The high dose group has the best effects and less adverse reaction.