To breed new Mei cultivars with cold-resistant and blossom early characteristics,we investigated the interspecific compatibility between Prunus mume and P.davidiana by observing fruit set and the pollen tube growth by means of fluorescence microscopy,and immature embryo culture.Results showed that:(1)The fruit set was quite low in all crosses,especially the cross of P.mume ‘Jiangmei’×P.davidiana ‘Alba’failed to form fruits.The cross of P.mume ‘Dan Fenghou’×P.davidiana obtained the highest fruit set 7.4%,and part of fruits were abortive.(2)After cross-pollination,the pollinations of P.davidiana and P.davidiana ‘Alba’ could germinate normally on the stigma of P.mume,but the pollen tube growth was hindered along the style.A higher number of pollen tubes stopped growing when reaching the middle section of the style,and some bended,twined and fractured,but no pollen tubes were observed reaching the base of the style or growing down to the ovary.A large amount of callose accumulated in the process of pollen tube growth which showed the cross-incompatibility.There were differences between cross combinations.(3)Hybrid has been successfully obtained by culturing immature embryo,which indicates that embryo rescue techniques facilitate hybrid creation.