Objective To repair the defects in articular cartilage with collagen complex gradient TCP in vivo andto study the regenerated cartilage histomorphologically. Methods The models of defects in articular cartilage were madeartificially in both condylus lateral is femoris of mature rabbits, male or female, with the weight of 2.0-2.5 kg. The right defects were implanted with the material of Col/TCP as the experimental group and the left defects were untreated as the control group. The rabbits were killed at 4, 6, 8, 12 and 24 weeks after operation, respectively, with 6 ones at each time, and the macroscopic, histological, ultrastructural examinations and semi-quantity cartilage scoring employing Wakitanifa repaired cartilage value system were performed. Results Four weeks after operation, the defects in the experimental group were partly filled with hyal ine cartilage. Twelve weeks after operation, the defects in the experimental group were completely filled with mature hyal ine cartilage. Twenty-four weeks after operation, regenerated cartilage had no ataplasia. However, fibrous tissues were seen in the control group all the time. At 4, 6, 8, 12 and 24 weeks ostoperatively, the Wakitanifa cartilage scores were 7.60 ± 0.98, 5.69 ± 0.58, 4.46 ± 0.85, 4.35 ± 0.12 and 4.41 ± 0.58, respectively, in the experimental group and 10.25 ± 1.05, 9.04 ± 0.96, 8.96 ± 0.88, 8.88 ± 0.68 and 8.66 ± 0.54, respectively, in the control group. At 4, 6, 8, 12 and 24 weeks postoperatively, the collagen II contents were 0.28% ± 0.01%, 0.59% ± 0.03%, 0.68% ± 0.02%, 0.89% ± 0.02% and 0.90% ± 0.01%, respectively, in the experimental group, while 0.08% ± 0.02%, 0.09% ± 0.04%, 0.11% ± 0.03%, 0.25% ± 0.03% and 0.29% ± 0.01%, respectively, in the control group. Differences between the control group and the experimental group were significant (P lt; 0.05). By then, typical chondrocyte was observed by transmission electron microscope in the experimental group and much fiber with less fibrocyte was observed in the control group. Conclusion Three-dimensional scaffold collagen complex gradient TCP may induce cartilage regeneration to repair the defects of articular cartilage in vivo.