Th is paper aim s at help ing f irm s to def ine the reasonab lemo t ivat ion by view of su stainab le developm en t st rategy. O n ly w hen the f irm s imp lem en tM &A by con st ruct ing and cu lt ivat ing their co re competency, can the new o rgan ic bodies in tegrate effect ively. Then, the new bodies can realize the coo rdinate and su stainab le developm en t. By analyzing the relat ion betw eenM &A and con st ruct ion and cu lt ivat ion of co re competency, the paper p resen t s an overall f ram ewo rk of models of M &A based upon the f irm s’ co re competencies. Then, it discu sses the concrete models of M &A , nam ely m anaging2capab ility2based co re competency, m arket ing2capab ility2based co re competency, technovat ion2capab ility2based co re competency, cu ltu re2pow er2based co re competency.