Abstract. In order to explain the mechanism of the calcium oscillations induced by the calcium-induced calcium release in non-excitable cells, the Kummer-Olsen calcium oscillation model was proposed. In this paper, by using the qualitative theory, bifurcation theorem and the center manifold theory, the nonlinear dynamics of this model is first characterized, including the stability and classification of the equilibrium points with parameter value. It is shown that supercritical Hopf bifurcations play very important roles in calcium oscillations. Furthermore, some new numerical simulations have confirmed the theoretical analysis results. Based on the existing numerical results with the theoretical analysis, complex dynamics of the Kummer-Olsen calcium oscillation model has been described perfectly.