We consider a non-autonomous competitive model with generalized functional responses for interaction among n species, the adult members of which are in competition. For each of the n species the model incorporates a distributed time delay which represents the time from birth to maturity of that species. Based on some comparison arguments, we discuss the permanence and extinction of the species. By virtue of the continuation theorem of coincidence degree theory, we prove the existence of a positive periodic solution. By means of constructing appropriate Lyapunov functionals, we obtain sufficient conditions for the uniqueness and the global stability of the periodic solution. Two examples are given to illustrate the feasibility of our main results.