QADE - program for qualitative analysis of differential equations. The authors give a description of the software package QADE (Qualitative Analyzer of Differential Equations) for the qualitative analysis of nonlinear autonomous second order differential equations F(x,x ’ ,x ” )=0, that provides the coordinates and the nature of all existing fixed points, the phase portrait, the time dependency of the solution, spectral characteristics, the Poincaré’s intersections and the Lyapunov exponents. A few examples include the Van der Pol’s equation, the Duffing’s equation, and the Liénard’s equation.