This study deals with the accident models of rotary, The objectives is to develop the models by day and nightime. In pursuing the above, this study gives particular attentions to collecting the data of geometric structure and accidents of 20 rotaries and developing the Poisson and negative binomial regression models using NLOGIT 4.0. The main results are as follows. First, the numbers of accident of nighttime (1 .03 per 1,000 entering vehicles) were analyzed to be very higher than those of day (0.47 per 1,000 entering vehicles). Second, 4 Poisson models which were all statistically significant were developed, in which the dependent variable were both the number of accident and EPDO (equivalent property damage only). Finally, the number of entry/exit (X1) and the number of entering lane (X5) in the models of the number of accident, and X1 in the EPDO models were adopted as the common variables. The variables were analyzed to be all positive to the dependent variables.