Objective To study NonO protein expression changes in murine erythroleukemia ( MEL ) cell differentiation induced by sodium butyrate .Methods Benzidine staining was used to test sodium butyrate-induced erythroid differentiation of MEL cells .We detected NonO protein expression changes in MEL cell differentiation induced by sodium butyrate and NonO protein localization in MEL cells by Western blotting and immunocytochemistry .Furthermore , we applied PCR technique to detect NonO RNA expression in differentiation process .Results We found that NonO protein was upregulated at gene and protein levels in the erythroid differentiation process of MEL cells induced by sodium butyrate and located in cytoplasm and nucleus in MEL cells .Conclusion These results show that NonO protein is closely related with MEL cell differentiation induced by sodium butyrate , which may provide important clues for further study of the mechanism of leukemia .