Aiming at the stability problem of stochastic nonlinear systemsan aperiodically intermittent controller based on discrete observations is designed to ensure the mean square exponential stability of the closed-loop stochastic system.Different from the existing intermittent controllersthis intermittent controller is aperiodic.Moreoverthis controller is a discrete-time state observation based feedback controllerrather than a continuous-time feedback controller.Thenthe criterion of exponential stability is givenand the intermittent controller is designed according to the criterion of stability.The mean square exponential stability of the stochastic nonlinear system is proved by using Lyapunov theoryand the correctness of the criterion is verified.Finallythe validity of the analysis results is proved by numerical examples.