This work considered class singular bilinear stochastic systems in Langevin's form. The authors presented the definition and application of apparatus, a class of pseudo-semi-inverse matrices, and, for the first time, included Sh.S. Smagulov's initial condition for the class of singular nonlinear stochastic systems in bilinear case. The article considers a system in the form Map «Input – Output» for a class with several inputs in the Langevin's form.

On the base of connection between Langevin's form and Volterra's form are proved the theorem about the construction of Volterra`s model for a class of singular nonlinear stochastic systems in bilinear case. Also, authors proved theorems about uniqueness, convergence and finitely (on the base class of nilpotent matrices of S. Li) for this Volterra's model in Ito`s form in conception of describing the system in form Map « Input – Output » for the above class of systems, but with several inputs.

As well known in the problem statement for solving the singular system, in other investigations, initial condition stated, in our view, is incorrect, or this condition is absent. Therefor due to Sh.S. Smagulov's initial condition and on the base apparatus R.S. Sudakov's class of pseudo-semi-inverse matrices and using Sh.L.Sobolev's annulator can build solutions above named of a class of singular nonlinear stochastic systems in bilinear case.