[Authors] A. L. Chistov [Title] Polynomial--time computation of the degree of a dominant morphism in zero--characteristic I [AMS Subj-class] 14Q15 Higher-dimensional varieties [Abstract] Consider a projective algebraic variety $W$ which is an irreducible component of a set of all common zeroes of a family of homogeneous polynomials of degrees less than $d$ in $n+1$ variables in zero--characteristic. We show how to compute the degree of a dominant rational morphism from $W$ to $W'$. The morphism is given by homogeneous polynomials of degree $d'$. This algorithms is deterministic and polynomial in $(dd')^n$ and the size of input. [Comments] LaTeX, English, 32 pp. Published in Russian: Chistov A. L.: ``Polynomial--time computation of the degree of a dominant morphism in zero--characteristic I'', Zap. Nauchn. Semin. St-Petersburg. Otdel. Mat. Inst. Steklov (POMI) 307 (2004) p. 189--235. [Contact e-mail] sliss@iias.spb.su