Block copolymers of epsilon-caprolactone (CL) and l-lactide (l-LA) were synthesized by sequential polymerization using diphenylzinc as initiator. The composition of the copolymers was adjusted changing the comonomers in ratio. Copolymers were characterized by H-1-NMR, C-13-NMR, DSC, and GPC. Results indicate that poly(epsilon-caprolactone)-b-poly(l-lactide) (PCL-b-PLA) block copolymers had a narrow molecular weight distribution and well-controlled sequences without random placement.