Systems of parametrical lattice Boltzmann equations (LBE's) are considered. The formulae for the apparent viscosity for the general representation of these systems is obtained by Chapman - Enskog asymptotic expansion on Knudsen number. Obtained expression represents viscosity as a function of the relaxation parameter and parameter of the LBE's. Necessary stability conditions in form of inequalities are derived from the non-negativity condition of the apparent viscosity. The validity of the stability conditions are demonstrated by the solution of lid-driven cavity flow problem.