The subject of this paper is to give a summary of the more important techniques used in Identification of Physical Process, the purpose being that of serving as a bibliografical reference to future works (chap´s I, II and III). Special attention is given to problems of Identification in time varying systems, with the object the designing Auto-Adaptive Control Systems. Methods of Identification were developed using Adaptative Model Technique (Chap IV). Analog simulation of the adaptative model was performed on the ANALAC (Alternating Current Analog Computer) utilising the GEL and CI Integrator Modules. The simulation results were verified by testing the convergence of various examples, whose solutions are well know. The results are given in the Anex 1. In addition the feasibility of solving this same problem on a digital computer (IBM 1130) was considered (chap IV. 3). In the Anex 2, FORTRAN programs of the digital technics are presented.