Abstract: Caragana intermedia were treated with different concentrations of colchicine solution at different stages in order to figure out the best inducing method and obtain polyploids. The results indicated that the mutation rate of seeds was 53.3% with the treatment of 0.3% colchicines for 48 h，while for sprouting seeds immersed in 0.15% colchicines for 36 h，the mutation rate was 73.3%. Chromosome observation found that the chromosome number of mutated plants was 2n = 4x = 32（tetraploid）and 2n = 3x = 24（triploid），while that of the control plants was 2n = 2x = 16. The chimera was also found among treatment plants. A few polyploid seedlings were obtained in this study，this will provide the good base for Caragana polyploid breeding.

Key words: Caragana intermedia, polyploid, colchicine