Abstract: In this paper,we establish the existence of a positive periodic solution for#br#N'(t)=r(t)N(t)[1-N(t-τ)/k(t)],#br#and we obtain sufficient conditions for uniqueness and global attractivity of the positive periodic solution. Our results extend and improve the correspond ones in[1].

Key words: Delay-Logistic equation, periodic solution, global attractivity, oscillation, nonoscillation