In recent years,singular stochastic systems governed by the Itô stochastic differential equation have received much attention due to their extensive applications to some practical areas.However,it is very complicated to discuss singular stochastic systems since the system equation includes both the singular matrix and the diffusion matrix simultaneously.In this paper,research development of several important and basic problems for singular Itô stochastic systems are concluded,including mainly the existence condition for the solution to the system equation,the general Itô formula,the definition of admissibility and the issue of stability.Also,some research perspectives are given for results of different references.Finally,some prospects to the unresolved problems are presented.