This paper studied the multitimescale synchronization and transitions of symmetrically coupled modified ML neurons with chain and ring coupling schemes. By defining the functions of spike phase, burst phase, mean frequency difference of spike and burst, we find that, with the increase of coupling strength, the coupled neurons can transit from irrelevancy to burst synchronization, then to spike synchronization and finally to a nearly complete synchronized state. Burst and spike synchronization belong to phase synchronization, and spike synchronization corresponding to the fast time scale may take place before burst synchronization, which corresponds to the slow time scale. Moreover, these two forms of rhythm synchronization don’t involve each other, but may coexist within certain limits of coupling strength. Besides, with the help of ISIs bifurcations, some complex firing patterns and bifurcations can be found during the synchronization transitions.