本文研究范畴中态射乘积ggq的广义逆．假设有态射p'和q',使得p'pg＝g＝gqq'．分别用g~+和g~#给出了乘积Pgq的Moore－Penrose逆和Drazin逆存在的充要条件及其表达式．

In this paper we research generalized inverse of product f = pgq in categories.Suppose these exist morphism p' and q' such p'pg = g = gqq', we characterize theexistance of the Moors-Penrose inverse f+ and the Drazin inverse fD in terms of g+and g# respactively, and establish the expression of f+ and fD.