Objective To explore the possible mechanism of Bushen Shuji Granules（补肾舒脊颗粒

BSG） in delaying heterotopic ossification. Methods Human bone marrow mesenchymal stem cells（BMSCs） were cultured in vitro and divided into blank group

model group

control group and Chinese medicine high

medium and low dose groups. The blank group was cultured with basal medium（3. 8 ml） + 5% normal rat serum（0. 2 ml）; the model group was cultured with induction medium（4. 8 ml） + 5% normal rat serum（0. 2 ml）; the control group was cultured with induction medium（3. 8 ml） + 5% loxoprofen sodium containing serum（0. 2 ml）; the Chinese medicine high

medium and low dose groups were cultured with induction medium（3. 8 ml） + 5% BSGs containing serum（0. 2 ml）. After 28 days

the mRNA and protein expressions of Wnt5 a and β-catenin were detected by reverse transcription-polymerase chain reaction（RT-PCR） and Western blotting. Results Compared with those in the blank group

Wnt5 a and β-catenin protein and mRNA expressions in the model group significantly increased（P < 0. 05 or P < 0. 01）. Compared with those in the model group

the mRNA and protein expressions of Wnt5 a and β-catenin in the control group and Chinese medicine high

medium and low dose groups decreased（P < 0. 05 or P < 0. 01）; compared with those in the control group

the mRNA expressions of Wnt5 a and β-catenin in Chinese medicine high dose group decreased

while the protein expressions of Wnt5 a and β-catenin in Chinese medicine medium dose group decreased（P < 0. 05 or P < 0. 01）; compared with those in Chinese medicine low and medium dose groups

the mRNA expressions of Wnt5 a and β-catenin in the high dose group decreased（P < 0. 05 or P < 0. 01）. Compared with those in Chinese medicine low dose group

the Wnt5 a protein expression in the medium-dose group decreased

and the β-catenin protein expression in the high-dose group increased（P < 0. 05）. Conclusion BSG may inhibit the mRNA and protein expressions of Wnt5 a and β-catenin through the Wnt/β-catenin signaling pathway

which can delay the heterotopic ossification of ankylosing spondylitis.