Objective:To evaluate the biocompatibility of graphene/nano-hydroxyapatite/polyamide 66 composite material. Methods:G/n-HA/PA66 composite was prepared by solution blending method. Material extract solution was extracted as specified by GB/T16886.5-2003/ISO 10993-5:2009. The experiments were divided into 3 groups:experimental group

negative control group

and positive control group. The biocompatibilities of G/n-HA/PA66 composite were evaluated according to in vitro cytotoxicity test

acute systemic toxicity test

hemolysis test

pyrogen test and intradermal stimulation test. Results:In vitro cytotoxicity test showed that the cell morphology and proliferation had a good condition and there was a significant statistical difference between each experimental group and positive group（P=0.000）. The cell cycle of C3H10T1/2 in G2/M and S period could not be affected by composite material（P =0.889）. The cell apoptosis could not be promoted by composite material（P=0.988

P=0.919

P=0.781）. Acute systemic toxicity test showed that the mice weight of experimental group[（33.30±3.81）g] had no statistical significance with control group[（31.08±2.91）g]（P=0.166）and there was no death and toxicity effect in mice. Hemolysis test showed that the hemolysis rate of G/n-HA/PA66 composite was（0.97±0.36）%

which fitted the evaluation criteria of less than 5%（P=0.000）. Pyrogen test showed that the increased temperature of experimental animal was（0.25±0.12）℃

which fitted the evaluation criteria of less than 0.6 ℃（P=0.035）. Intradermal stimulation test showed that the phenomena such as erythema and edema were not observed around the injection point in the ex-perimental group and control group

and the PII scores indicated the most slightly stimulation. Conclusion:G/n-HA/PA66 composite had excellent biocompatibility and practicability as a bone fixation implant.