Let be a polynomial dominant mapping and let deg f i≤ d. We prove that the set K( f) of generalized critical values of f is contained in the algebraic hypersurface of degree at most D=( d+ s( m−1)( d−1)) n, where . This implies in particular that the set B( f) of bifurcations points of f is contained in the hypersurface of degree at most D=( d+ s( m−1)( d−1)) n. We give also an algorithm to compute the set K( f) effectively.