Abstract:The hard seed rate of untreated Cassia occidentalis Linn. is high and the germination rate is low due to its hard seed coat. To study the effects of different treatments on seed germination and seedling growth of C. occidentalis, concentrated sulfuric acid treatment, soaking treatment with hot water, and drying treatment in high temperature were used in this experiment. The results showed that the treatment of concentrated sulfuric acid could significantly improve the seed germination of C. occidentalis. Especially the treatment with 98% concentrated sulfuric acid for 30 min, the hard seed rate was decreased to0. 0%, the germination rate was 79. 00%, germination potential was 76. 00%, germination index was99. 17, vitality index of seed was 9. 04, which were 1. 25, 1. 23, 1. 51 and 1. 91 times as much as that of the control group, respectively. Cotyledon length, cotyledon width, seedling biomass were also significantly improved compared with the control. Although soaking seeds with hot water and drying treatments had no obvious effects on the seed germination of C. occidentalis, these two treatments could prominently promote the growth of seedlings. The seed germination and seedling growth of C. occidentalis could be inhibited by soaking seeds in hot water or drying while the temperature was too high.