Oscillations in intracellular free Ca2+ concentration ([Ca2+](i)) have been observed in a variety of cell types. In the present study, we constructed a mathematical model to simulate the caffeine-induced [Ca2+](i) oscillations based on experimental data obtained from isolated type I horizontal cell of carp retina. The results of model analysis confirm the notion that the caffeine-induced [Ca2+](i) oscillations involve a number of cytoplasmic and endoplasmic Ca2+ processes that interact with each