Abstract: OBJECTIVE To explore the correlation between the expression of osteoclast-related cytokines like MCSF， RANKL， TNFα IL1αin patients with osteoporosis and TCM syndromes. METHODS 120 cases with osteoporosis were divided into the kidney yang deficiency group(30 cases)， deficiency of spleen and stomach group(30 cases)， liver-kidney yin deficiency group(30 cases) and qi stagnation and blood stasis group(30 cases) based on syndrome differentiation. Fasting blood samples early in morning were collected and the expression of four items including MCSF， RANKL， TNF and IL1αwere tested by applying euzymelinked immunosorbent assay method. RESULTS Kidney yang deficiency group experienced evident lower expression of MCSF and RANKL than the other three groups， with significantly statistical differences， while no differences were noticed in the expression of TNFαand IL1αamong the four groups. CONCLUSION Detection of MCSF and RANKL expression can be considered as an effective way to distinguish the kidney yang deficiency syndrome from the other three types. Hence， we believe that there exists quantified objective evidence for osteoporosis syndrome differentiation in TCM.