An early embryo co-culture system with human decidual stromal cells was established to study its effect on early embryonic cleavage and growth in vitro. Three hundred and eight 2-cell mouse embryos were co-cultured with human decidual stromal cell monolayer in MEM+0.4%bovine serum albumin (BSA) and 163 embryos cultured in MEM+15 % FCS alone as control. Among the mouse 2-cell embryos co-cultured with human decidual stromal cells, 72.73% developed to the morula stage and 67.21% cavitated to blastocysts with 59.74 % hatching, as compared with 61.34% to morula stage, 48.47% to blastocysts and none hatching in the controls,respectively. Co-cultured embryos cleaved slightly faster than controls and showed no or less fragmentation than those in the control. These results suggested that human decidual stromal cells can support early embryonic development and yield a reasonable number of embryos with good quality up to blastocyst stage.