Retinal bipolar cells according to the light stimulus respond to potential slowly, emit neurotransmitter release(glutamine acid) to depend on membrane potential. In this paper, the several physiological information on neurotransmitter release mechanism in the presynaptic terminal of the ON-type bipolar cells are incorporated into the formula model. The source of fast components and slow components of neurotransmitter release was arranged in parallel, this model was able to reproduce the membrane potential and intracellular $Ca^{2+}$ concentration dependence of neurotransmitter release faithfully. In addition, because the fast releasable components of neurotransmitter was represented by the membrane potential dependence of trapezoid type, whereas the slow releasable components was represented by the membrane potential dependence of a bell type, $Ca^{2+}$ concentration rise in intracellular is suppressed by $Ca^{2+}$ buffer to reduce slow releasable components, it was confirmed that the membrane potential dependence of neurotransmitter release was characteristics of a trapezoid type. And, in the light response of ON type bipolar cell, the result of the simulation of the neurotransmitter release caused by the components of transient and persistent was that the start of light response occurred the fast release of neurotransmitter, it was confirmed that the transient component and persistent component of the light response occurred the slow release. It was confirmed that the later of persistent component of the light response occurred due to the continuous release by synaptic vesicle supplemented from the storage pool.