[Objective] This study aimed to induce the tetraploid of Clematis heracleifolia. [Method] Mixture of 0. 2% colchicine solution and 1% agar were heated into a gel smeared on the apical meristem top bud of Clematis heracleifolia seedling to induce its tetraploid. The induction lasted for 24,48 and 72 h respectively in three treatments to determine the best induction time. Finally,the morphological and cytological characteristics were identified and compared between the mutants and the controls. [Result] The variation rate was the highest,up to 80% when the induction time was 48 h. Compared with controls,the leaf of mutant was longer,wider and thicker,and the leaf index was smaller. The stomata size and density of lower leaf epidermis between the mutants and controls were significantly different. Chloroplast number in guard cells and chlorophyll content of mutants were all increased significantly compared with the controls through microscope observation of lower leaf epidermis and SPAD value. Chromosome number of most mutants was 32(2n = 4x),while that of controls was 16(2n = 2x) by cytology observation of root tip cells. [Conclusion] Tetraploid of Clematis heracleifolia was successfully obtained. [Objective] This study aimed to induce the tetraploid of Clematis heracleifolia. [Method] Mixture of 0.2% colchicine solution and 1% agar were heated into a gel smeared on the apical meristem top bud of Clematis heracleifolia seedling to induce its tetraploid. The induction lasted for 24, 48 and 72 h respectively in three treatments to determine the best induction time. Finally, the morphological and cytological characteristics were identified and compared between the mutants and the controls. [Result] The variation rate was the highest, up to 80% when the induction time was 48 h. Compared with controls, the leaf of mutant was longer, wider and thicker, and the leaf index was smaller. The stomata size and density of lower leaf epidermis between the mutants and controls were significantly different Chloroplast number in guard cells and chlorophyll content of mutants were all increased significantly compared with the controls through microscope observation of lower leaf epidermis and SPAD va Chromosome number of most mutants was 32 (2n = 4x) while that of controls was 16 (2n = 2x) by cytology observation of root tips cells. [Conclusion] Tetraploid of Clematis heracleifolia was successfully obtained.