Recently, the nonlinear dynamics and chaos phenomenon of many neuron models have been studied. This paper provides a global picture of the bifurcation scenario of the Hindmarsh-Rose model and studies one point of every scenario. We use chaotic method to analyze phase plot, nullclines, entropies and dimensions of the chaotic point, from which we might find some useful mechanisms to understand the characteristics of neuron behaviors. Finally we can find that there are some relationship between the correlation dimension, approximate entropy and the maximum Lyapunov exponent.