Objective To observe the effects of insulin-like growth factor-2 (IGF2) in the course of mouse embryon-ic stem cells induced to differentiate into islet-like cells. Methods Mouse ES cells were induced to differentiate into islet-like cells in vitro. The expression of islet specific markers was tested by RT-PCR and immunofluorescence assay. RT-PCR/RFLP was used to test the imprinted genes IGF2 parental expression in cells at different stages. Results Islet specific mark-ers were expressed in differentiated cells, such as insulin, glucagon and C-peptide. PCR-RFLP showed that imprinted genes IGF2 derived from embryonic stem cells were biallelic expression and loss of imprinting. Conclusion Gene imprinting sta-tus of IGF2 was changed in differentiated cells in vitro.