The cross-compatibility between Primula forbesii (Sect.Monocarpicae.Ex Pax ) and P.saxatilis (Sect.Cortusoides Balf.f.) was investigated by seed-setting and observation of pollen tube behavior after interspecific crosses.The results showed that no normal seeds were obtained from reciprocal crosses between the two Primula species.The pollens of P.forbesii were able to germinate at the stigma surface of P.saxatilis in 4 hours after pollination.However,pollen germination significantly lagged behind the control groups [P.saxatilis (P)×P.saxatilis (T),P.saxatilis (T)×P.saxatilis (P)] and the pollen tube elongation was hindered so that the pollen tubes could not extend into the ovary in 192 hours after pollination.The pollens of P.saxatilis germinated successfully at the stigma surface of P.forbesii and the pollen tubes elongated into the ovary in 48 hours after pollination.The pre-fertilization barriers was observed in P.saxatilis×P.forbesii,while P.forbesii×P.saxatilis showed good interspecific compatibility,and the hybrid seedlings have been attained by embryo rescue.The length of stigmas may be one of the factors that influence the compatibility of interspecific hybridization.