In this paper, we propose a probabilistic neurotransmitter release for Dynamic Synapses Neural Network (DSNNs). The capabilities of DSNNs have already been investigated in the processing of spatio-temporal patterns of action potentials [Jim-Shih Liaw and Theodore W. Berger, 1996]. The deterministic model of synapse is substituted by probabilistic Markov model. The action potentials generated by auditory system are the inputs of the model. The probability of neurotransmitter release is then estimated from the model. In general, the aim of this study is to present a robust pure tone recognition system based on DSNN. To generate action potential from music tone we have employed pulse code modulation method. The action potentials are plugged into the DSNN for recognition purpose. Our simulation results showed that the DSNN based on probabilistic release has 4% better recognition performance with respect to the deterministic model [Alireza A. Dibazar and et al., SFN 2002]. This work supported in part by DARPA-C...