The　geodesic　active　contour　(GAC)　model　has　been　widely　used　due　to　the　high　precision　of　edge　detection　and　the　continuity　of　boundaries.　However,　compared　to　the　gradient　vector　flow　(GVF)　field,　it　usually　has　poor　performance　in　the　object　boundaries　with　concave　shape.　In　this　paper,　the　improvements　that　integrate　the　good　performance　of　the　GAC　model　and　the　GVF　field　are　described　in　detail　and　the　GAC-GVF&B　model　combining　the　GAC　model　with　the　GVF　field　and　a　balloon　force　is　proposed.　The　experimental　results　demonstrate　that　the　proposed　method　is　insensitive　to　the　positions　of　initial　curves　and　can　segment　complex-shape　or　multi-objects　images　correctly　with　higher　convergence.　©　2015,　Multi-Science　Publishing　Co.　Ltd.