Abstract: Histone deacetylases （HDACs） are key proteinases involving in gene regulation. Acetylation is a reversible covalent modification action for protein. HDACs are able to regulate the transcription and expression level of a specific gene and to induce cell differentiation and apoptosis. The aim of the present study was to assess the effect of a novel type of HDACs, Scriptaid, on development of cloned embryos in swine. The cloned pig embryos were treated with different concentrations of Scriptaid for different duration. The cleavage rate and developmental ability of the embryos were determined in vitro. The fetal fibroblasts of landrace pig from Lingyuan Hefeng Pig Breeding Farm were used as donor cells and the embryos were obtained by somatic cell nuclear transfer （SCNT） technology. The reconstructed embryos were treated with different concentrations of Scriptaid （0, 200, 500, 700, 900 nmol/L） for 0, 15, 36, 72 hours, respectively. The cleavage rate and blastocyst development rate of the embryos in two-cell stage were determined. The relative expression of Oct4 and Sox2 genes of the embryos in two-cell stage in untreated group and Scriptaid treatment group were evaluated by using Real-time assay. The results showed that compared to the untreated group, the 500 nmol/L Scriptaid treatment group had significantly higher blastocyst development rate （P〈0.05）; no significant differences were observed in cleavage rate of embryos in two-cell stage. In blastocyst stage, the relative expression of Oct4 gene of the cloned embryos in untreated group was significantly lower than that in Scriptaid treatment group （P〈0.05）, indicating that the relative expression of Oct4 gene of the cloned embryos was significantly increased after the treatment of 500 nmoFL Scriptaid; no significant differences in the relative expression of Sox2 gene of the cloned embryos between untreated group and Scriptaid treatment group were observed （P〉0.05）, indicating that although the relative expression of Oct4 gene was increased after the treatment of 500 nmol/L Scriptaid, there were no significant differences between control group and Scriptaid treatment group.