Objective: The aim of this study was to assay the expression profile of MCT1,2,3,4 in 4-cell Fresh and 4°C mouse embryoes. Materials and Methods: NMRI female mice on a fixed light-dark cycle were exposured by interaperitoneal injection of 10 IU PMSG and followed 48 h later by 10IU hcG.injected mice mated with mature male NMRI mice.After view the vaginal plug,4-cell embryoesoe obtained from mice that killed by cervicaldislocation at 52-55 h post hcG injection respictievly.Embryoes separated to 2 groups:1. Fresh group consist of 4-cell embryos in KSOM.2. 4°C embryos in KSOM with 24 h incubation in 4°C.The presence of mRNA encoding MCT 1,2,3,4 at each group were demonstrated by RT-PCR kit on , and products of PCR loaded on 3% Agarose gel. Results: MCT1 expressed in Fresh and 4◦C groups.neither MCT 2 nor MCT3,4 expressed in each 2 groups. Conclusion: MCT1 have a major role in development of mouse embryo.It expression is same in Fresh and 4◦C mouse embryoes. Not only MCT2 but also MCT3,4 not expressed in Fresh and 4°C embryoes.