Objectives: In the recent ten years, prefabricated carbon fiber post-core system is widely used in the west and recognized as a valid alternative to conventional metallic posts for reconstruction of residual roots and crowns. The present study aims to primarily screen four types of carbon fiber post materials (PI1-4) produced by Institute of chemistry, Chinese Academy of Sciences beginning with bilolgical properties. The qualified samples can be expected to enter the next stage of tests for the earlier clinical application. Methods: The first stage: In vitro preliminary screening tests Materials: PI1-4 Methods: 1. Cytotoxicity test: L-929 cell viability and proliferation were tested by MTT assay. 2. Hemolysis test: Hemolysis percentage measurement was used to assay the hemolytic properties. From above tests, one material with highest biocompatibility was permitted to the next tests. The second stage: In vivo Animal tests Materials: The carbon fiber post which had been screened through the first stage. Methods: Subcutaneous implant test and bone implant test were involved in the study. Materials were implanted into subdermal tissues and tibias respectively in rabbits, and animals were sacrificed after 2, 4and 8 weeks. Macroscopic inspection and histological assessment of the implantation site were required. Results: The first stage 1. The cytotoxicity of PI1-4 was grade 1, up to standard. 2. The hemolysis rates of PI1-4 were less than 5%, up to standard. 3. PI4 was recognized as the screening to the next tests with the best nature relatively. The second stage 1. Subcutaneous and bone implant tests both indicated that PI4 had not caused marked pathological inflammatory responses. Conclusions: In vitro and in vivo Studies had shown: Native carbon fiber–reiforced composite PI4 had good biocompatibility and the further steps could be taken to study deeply for the earilier clinical application.