Aim To investigate the effect of paclitaxel on the time course of rabbit vascular smooth muscle cells (SMC) and endothelial cells (EC) growth. Methods In the cell coculture system, rabbit EC were seeded in the lower chamber and SMCs in the upper chamber. Four groups were divided: confluent EC group,proliferative EC group, EC control group and SMC control group. Paclitaxel of 10 nmol/L was added to the lower chamber of the confluent and proliferative EC group and act for 20 minutes. 3 H-TdR incorporation and cell counting were assayed respectively after 0, 1, 3, 7 and 10 d to determine the effect of paclitaxel on the time course of vascular EC and SMC growth. Results At 1 and 3 d after paclitaxel was added, the 3H-TdR incorporation and cell counting of SMC in the confluent and proliferative EC group were both significantly lower than those in the SMC control group (confluent EC group, proliferative EC group, 3 H-TdR incorporation was respectively: 1d:54%±4%, 56%±5%; 3 d: 65%±3%, 63%±3%; cell counting was respectively: 1 d: 64%±6%, 62%±4%; 3 d: 68%±5%, 66%±5%; n=6, p<0.05). The 3 H-TdR incorporation and cell counting of EC in the proliferative EC group were also significantly lower than those in the EC control group ( 3 H-TdR incorporation: 1 d: 75%±9%, 3 d: 81%±6%; cell counting: 1 d: 72%±7%, 3 d: 80%±7%; n=6, p<0.05). At 7 and 10d after paclitaxel was added, the 3 H-TdR incorporation and cell counting of SMC in the confluent EC group were still lower than those in the SMC control group ( 3 H-TdR incorporation: 7 d: 69%±5%, 10 d: 73%±4%; cell counting: 7 d: 72%±5%, 10 d: 76%±6%; n=6, p<0.05). However, the 3 H-TdR incorporation and cell counting of EC in the proliferative EC group have no statistical significance compared with the EC control group( 3 H-TdR in-corporation: corporation: 7 d: 97%±5%, 10 d: 101%±4%; cell counting: 7 d: 95%±4%, 10 d: