Objective To investigate the effects of different concentrations of lauromacrogol intravenous injection on the thrombosis and vascular walls through the animal experiment.Methods Thirty ear marginal veins of rabbits whose weight ranged from 2.5 kg to 3.0 kg and whose sex was not limited were divided randomly into six groups:1.0 ％ lauromacrogol group,0.9 ％ lauromacrogol group,0.8 ％ lauromacrogol group,0.7 ％ lauromacrogol group,0.6 ％ lauromacrogol group and normal saline group.The local veins and their side tissue were cut off for samples for HE staining and VEGF expression detected by immunohistochemistry at the first day,third day,fifth day and seventh day after injection.Results Visual observation and HE staining showed that 1.0 ％ lauromacrogol group,0.9 ％ lauromacrogol group,0.8 ％ lauromacrogol group and 0.7 ％ lauromacrogol group had thrombosis in veins after injection,0.6 ％ lauromacrogol group and normal saline group did not have thrombosis in veins after injection.The score of VEGF expression showed that 1.0 ％ lauromacrogol group,0.9 ％ lauromacrogol group,0.8 ％ lauromacrogol group and 0.7 ％ lauromacrogol group did not have statistically significant differences between groups and different time point (P＞ 0.05) and there were statistically significant differences between 0.6 ％ lauromacrogol group and other four groups (P＜0.05) in each time point.Conclusions From these animal experiments lauromacrogol shows the effect of vascular injury and thrombosis,eventually leading to the injected vein disappeared in 0.7 ％ lauromacrogol group.