In vitro development of porcine embryo is affected by culture condition. One possible factor is osmolarity of culture medium. 1his study examined whether high osmolarity of culture medium at the early culture stage improves development of preimplantation porcine in vitro fertilization (IVF) and nuclear transfer (NT) embryos. NT and IVF embryos were divided into three groups and the basic medium was PZM-3 ($250{sim}270$ mOsmol, control group). The control group of embryos was cultured in PZM-3 for whole culture period. Other two groups of embryos were cultured in a modified PZM-3 with 0.05 M sorbitol or 0.05 M sucrose ($300{sim}320$ mOsmol, sorbitol or sucrose group) for the first 2 days, and then cultured in PZM-3 for further culture. NT embryos cultured in sucrose group showed a significantly higher developmental rate to the blastocyst stage with a decreased apoptosis rate compared to the sorbitol (p<0.05). For IVF, sucrose group showed a significantly increased the blastocyst formation rate with a decreased apoptosis rate compared to the control (p<0.05). This study represents that the high osmolarity in the early embryo culture stage can enhance the in vitro development of porcine NT and IVF embryos to the blastocyst stage with reduced apoptosis of cells.