Abstract: In this paper, MCPET pellets made by ourselves were mixed with PTT pellets, then the MCPET/PTT blend fibers were obtained by melt spinning under 238℃. FTIR spectrum of the blends obtained show that there is no significant peakshift or the generation of new peaks, indicating that transesterification reaction and terminal group reaction didn’t exist in the blends .The compatibility of MCPET/ PTT blends was studied by DSC, DMA, WAXD and SEM. The results of DMA and DSC show that MCPET is well matched with PTT in the amorphous region; WAXD indicates that the crystalline region was partly compatible; Fracture morphologies explored by SEM indicate that the two materials have good compatibility.