The main propose of this repo1t is to present the analysis of phase transitions in the presence of an intennediate state by using the model with two order parameters. The parametric modelling of phase transitions and analysis of the role of an inte1mediate liquid state in ineversible relaxation processes at low temperatures were perfonned. As an example, one can consider the systems with two stable states LI and C that means liquid and c1ystalline, respectively, and the third one - intennediate fluid state, namely L2 [1]. Such L2 state has been experimentally discovered in supercooled liquids [2]. The model includes two order parameters and three control parameters in the Landau-type kinetic general potential of 6th degree, and has been developed to study the impact of heterogeneity on phase transitions in the presence of an inte1mediate fluid state [3]. We noticed that the presence of the intennediate liquid state may indeed enhance the nucleation rate, and, fmthennore, an increase in the heterogeneity of system accelerates the transition dynamics. In the previous works, we have shown that, depending on the values of its control parameters, the potential has one, two or three possible minima, and the problem dealt with the constrnction of the equilibrilllll phase diagrams. It is also w01th mentioning that the previously obtained results are general and suggest a complete set of different transition scenarios in the entire parameter plane with two control parameters [4]. We study next the stability and bifurcation of equilibrilllll states in the kinetic processes conesponding to the first-order phase transitions in systems which can be characterized by several order parameters. Along with general analysis when the kinetic processes conesponding to phase transitions in systems characterized by r nlllllber of order parameters x1 ,x2 , ••• , X7 and m nlllllber of control parameters ai ,a2 , ... , am are described by a system of ordinaiy differential equations of the form dxr = .f,.(x1 ,x2, ••• ,x7 ;a1 ,a2, ••• ,am), where t is time, the results of specific calculations for dt systems described by the kinetic Landau-type potential with two pai·ameters are also presented. In general, the lai·gest and smallest values of order pai·aineter for the bifurcation analysis conespond to minima of free energy functional F, while the inte1mediate value conesponds to an unstable state (F has a local maximum or saddle point), and these three extrema ai·e identified with the crystalline and two liquid phases [5]. In case of a single - component glass which can be characterized in te1ms of the pressure P and volllllle V, the relation between P and V could be obtained using the equation P(V,T,x,y) = -(oF I oV)r.x.y . Note that P(V,T,x,y,) can be derived from experimental data and this equation may be fuither used to dete1mine the V-dependence of F(V,T,x,y,) Then F can be applied to get the entropy S = -(oF I oT)v.x.y, and in this way specific heats and other the1modynainic quantities for the system can be defined [ 6].