Abstract: Objective: To observe the clinical effect of modified Sijunzi Decoction combined with western medicine for vitamin D-deficient rickets. Methods:A total of 60 cases of children with vitamin Ddeficient rickets were divided into the treatment group and the control group according to the random number table method,with 30 cases in each group. The control group was treated with Calcium Carbonate D3 Granules and Vitamin AD drops,and the treatment group was additionally treated with modified Sijunzi Decoction based on the treatment of the control group. Both groups were treated for six months. The clinical effects, traditional Chinese medicine(TCM) syndrome scores, bone mineral density, blood biochemical indexes and incidence of adverse reactions in the two groups were compared. Results: The total effective rate was 93.33% in the treatment group,higher than that of 73.33% in the control group(P< 0.05). After treatment,the TCM syndrome scores in the two groups were decreased when compared with those before treatment(P<0.05),and the bone mineral density value were increased(P<0.05);the TCM syndrome scores in the treatment group was lower than that in the control group(P<0.05),and the bone mineral density value in the treatment group was higher than that in the control group(P<0.05). After treatment,the levels of 25-hydroxyvitamin D3[25-(OH) D3] and blood calcium in serum in the two groups were increased when compared with those before treatment(P<0.05), and the levels of serum bone- specific alkaline phosphatase(NBAP) were decreased(P<0.05). The levels of serum 25- (OH)D3 and blood calcium in the treatment group were higher than those in the control group(P<0.05),and the level of serum NBAP in the treatment group was lower than that in the control group(P<0.05). The incidence of adverse reactions was 6.66% in the treatment group and 9.99% in the control group,there being no significance in the difference(P>0.05). Conclusion: The therapy of modified Sijunzi Decoction combined with western medicine for vitamin D- deficient rickets has a significant clinical effect, and is beneficial to promote the improvement of symptoms,enhance the bone mineral density and regulate the levels of blood biochemical indexes,with high safety.