The complex nonlinear features of the fast and slow dynamics in single map-based oscillatory neuron are studied through phase portrait analysis. The map-based model can exhibit a wide variety of oscillatory activity patterns found in real biological neurons. The nonlinear dynamics and phase synchronization of two chemically coupled maps are investigated with interspike interval (ISI) approach. Various interesting collective behavior of coupled neurons are presented. The effects of intrinsic properties of the individual neurons and chemical coupling scheme on phase synchronization are also discussed through numerical simulation.