This　paper　proposes　an　efficient　scheme　for　deterministic　generation　of　entangled　coherent　states　for　two　atomic　samples.　In　the　scheme　two　collections　of　atoms　are　trapped　in　an　optical　cavity　and　driven　by　a　classical　field.　Under　certain　conditions　the　two　atomic　samples　evolve　from　an　coherent　state　to　an　entangled　coherent　state.　During　the　interaction　the　cavity　mode　is　always　in　the　vacuum　state　and　the　atoms　have　no　probability　of　being　populated　in　the　excited　state.　Thus,　the　scheme　is　insensitive　to　both　the　cavity　decay　and　atomic　spontaneous　emission.