In this study, we present a method interfacial in situ polymerization of chitosan macromonomer (CM) to prepare biocompatible and biodegradable chitosan capsules, N, N'-methylene-bis-acrylamide (Bis) used as cross-linking agent. Methyl acrylic acid (MAA) is grafted onto the chitosan chain to obtain a water soluble double bond CM derivative. The molecular structure of chitosan derivative is confirmed by FT-IR and H-1 NMR. The oil soluble cumene hydroperoxide (CHPO) oxidizer and the water soluble reductant tetraethylenepentamine (TEPA) are used as redox initiation couple for producing radical at the oil/water emulsion interface when them encounter to initiate CM polymerization. The interfacial radical can in situ initiate CM to prepare capsules. The structure and morphology of the chitosan capsules are characterized by FESEM and TEM. All the results confirmed that the interfacial in situ polymerization can initiate double bond to prepare capsule at room temperature and under ambient pressure.