ASEAN Economic Community（AEC）is important one of the three pillars of ASEAN Community building and the progress of AEC is key part for the fulfillment of ASEAN Community. However，ASEAN announce the establishment of ASEAN Community at the end of 2015，with some targets listed by the AEC blueprint unfinished and left for the “post-2015” agenda. This is ASEAN’s new AEC promoting strategy that we can name it Jigsaw-Puzzle-Strategy. Under this new tactic，ASEAN try its best to finish sometargets of AEC building，while tolerating the less progress of other targets. The targets ASEAN choose to finish seriously are most important one for AEC，are those may helpdrawing out the image of AEC. Thus，ASEAN can make the AEC picture clearer step by step in the post-2015 era. This new strategy of ASEAN AEC building must have influences on RCEP negotiation，in which ASEAN want to play a central role.