Abstract: To improve the seed germination rate of Ormosia pinnata from Hainan and explore the reasons of difficult natural regeneration, the factors influenced seed germination and seedling growth of O. pinnata seeds were studied. The O. pinnata seeds were sown in 48 pots by orthogonal design experiment based on four factors and two levels with three repetitions. These factors included water（A）, light（B）, substrate（C） and seed coat（D）. The results showed that the seed germination rate was higher, the average germination rate of different combinations was 91.67%, and the initial time and sustaining time of germination was longer. Seed coat treatment（D） had significant effects on seed germination rate, germination rate, germination potential and germination index, while light（B） and substrate（C） had significant effects on seedling height. In addition, the best combinations of seed germination rate, germination rate and germination index were A₂B₂C₁D₁.The best combination for seedling height growth was A₂B₂C₂D₁.The results showed that the quality of O. pinnata seeds was good. Although the seed coat had a certain inhibitory effect on germination, it was not the direct obstacle factor restricting natural regeneration. Physiological characteristics and ecological conditions of seed germination might be the main limiting factors of natural regeneration.