The correlation of the embryo matrix metalloproteinase-9 (MMP-9) secretion, embryonic development and clinical pregnancy was investigated. The embryo culture from in vitro fertilization-embryo transfer (IVF-ET) patients were collected in the Xuzhou Central Hospital from January 2013 to September 2014. At the same time, the embryo grade was recorded. The secretion of the MMP-9 in the embryo culture was detected through hybridization (Dot-blot) and enzyme-linked immunosorbent assay (ELISA). The clinical pregnancy outcome was followed after one month of the embryo transfer. With the embryonic development from 2-cell to 8-cell, embryonic MMP-9 secretion increased gradually (p < 0.05). Though 8/I embryo, the secretion of MMP-9 are not identical. The quantitative detection of the MMP-9 secretion of the 8-cell embryo by ELISA is higher as is the embryo score, but the low secretion of embryo score is lower (p < 0.001). As 8/I embryos, the clinical pregnancy rate (77.3%) of the MMP-9 high secretion embryos is higher than the low secretion embryos (16.7%) (p < 0.001). The secretion of the embryonic MMP-9 is closely related to the quality of the embryo and embryo implantation. It is speculated that MMP-9 may become one of the criteria to evaluate the quality of the embryos.