To observe the effect of Zhibai Dihuang Pills（知柏地黄丸）on bone density and bone metabolism indicators in elderly patients with prostate cancer after drug castration treatment.

Eighty-two elderly patients with prostate cancer treated with drug castration were selected from the geriatric medicine department，general medicine department，oncology department，urology department，radiotherapy department and other outpatient departments and wards of Lianyungang Second People's Hospital. The patients were divided into the experiment group（42 cases）and the control group（40 cases）according to the random number method. Both groups received castration medicines. The control group received medication for castration in addition to calcium supplementation without any additional traditional Chinese medicine treatment. On the basis of the control group，the experimental group was additionally treated with Zhibai Dihuang Pills，with an observation period of 12 months. Total Prostate Specific Antigen（PSA），Free Prostate Specific Antigen（FPSA），Bone Density T-values（Lumbar L2～4，Femoral Neck，and Wards Triangle），as well as bone metabolism indicators，including bone glaprotein（BGP），C-terminal cross-linked telopeptides of type I collagen（CTX-I），bone alkaline phosphatase（BALP），25-hydroxyvitamin D［25（OH）D］and other indicators were recorded before treatment and at 3，6 and 12 months after treatment.

After 3 months of treatment，there was no significant difference in PSA，FPSA，bone density T-values（lumbar L2～4，femoral neck，Wards triangle）or bone metabolism indicators between the two groups. After 6 months of treatment，the index of BALP in the control group was radically higher than that in the experimental group，and the bone density T-values（lumbar L2～4，femoral neck，Wards triangle）were significantly higher than those in the control group（P<0.05），while there was no significant difference in other indicators. After 12 months of treatment，the levels of BALP and CTX-I in the control group were radically higher than those in the experimental group（P<0.05），bone density T-values（lumbar L2～4，femoral neck，Wards triangle），the levels of 25（OH）D and BGP were significantly higher than those in the control group（P<0.05），and there was no significant difference in other indicators. The comparison results before and after treatment within the experimental group showed significant differences in VAS scores. The bone metabolism indicators of the experimental group before and after treatment showed significant differences，except for the pairwise comparison of BALP treatment at 3 and 6 months，and those at 6 and 12 months（P<0.01，P<0.001）.

Zhibai Dihuang Pills can significantly improve osteoporosis in the elderly prostate cancer patients after drug castration treatment，increase the bone density，resist the oxidative stress and help to improve the quality of life of the elderly prostate cancer patients.