Abstract: Objective: To study the bio-compatible and toxic effects of the embeded immu-isolated membrane, the APA（alginate-polylysine-alginate） microcapsules. Methods: Transplanting different doses of APA microcapsules or APA microcapsulized bovine adrenal chromaffin cells（APA-BCC） into dorsal hypoderma or abdomen of the mouse, to observe changes of the microcapsule shape; to observe the normal activity, food taking and weight. Results: APA microcapsules mostly remained integrated 4 months after the transplantation; APA-BCC microcapsules mostly remained integrated after 2 months, but some were destroyed or enwraped after 4 months; The activity and food taking were normal after transplantation of high-dose or hyper-dose APA; There was no macroscopic abnormality in the abdomen and pathological changes in other important organs. Conclusion: APA microcapsule materials are remarkably harmless to bodies and of good bio-compatibility.