Objective To investigate the clinical efficacy and possible mechanism of Chinese Medicine Gutongling Formula（ 骨痛灵方

GTL） combined with Zoledronic Acid（ ZA） in the treatment of bone metastatic pain of lung cancer. Method A total of 73 patients with lung cancer bone metastasis who were suffering from moderate to severe pain were selected and randomly divided into control group（ 36 cases） and treatment group（ 37 cases）. The patients in both groups received analgesic and traditional Chinese medicine basic treatment

and the control group was additionally given intravenous infusion of zoledronic acid once 4 weeks. On the basis of the same treatment in control group

the treatment group was given oral GTL 1 dose each day

8 weeks as a course for both groups. Before and after the treatment

the numeric rating Scale（ NRS） was recorded to value the analgesia and the serum bone metablic markers serum calcium（ Ca2 +）

alkaline phosphatase（ ALP）

total procollagen type 1 N-terminal propeptide（ P1 NP） and β-isomerized C-terminal telopeptides（ β-CTx） were tested. The relevance of the linear of NRS and the reduce of serum bone metablic markers were analyzed. Results The total effective rate of analgesia in the treatment group and the control group was 72. 97% and 44. 44% respectively

and the differences between groups was significant（ P < 0. 05）. After treatment

serum ALP

P1 NP

β-CTx indexes of the treatment group decreased significantly（ P < 0. 05）

and the decrease was more than that of the control group（ P < 0. 05）. There was no significant of serum Ca2 +in both groups（ P > 0. 05）. According to the correlation analysis

the decrease of serum β-CTx was positively related to the reduction of NRS in the treatment group（ r = 0. 187

P < 0. 01）. Conclusion The prescription Gutongling Formula combined with ZA was an effective therapy for lung cancer bone metastasis with moderate to severe pain patients

and its mechanism may be related with the suppression of the osteoclasts activity.