In this study,hybridization was conducted between Rosa laxa（2n=2x=14）and Rosa cv.‘Kardinal’,‘Solidor’,‘Yuzen’（2n=2x=28）,and five,five and six F₁ hybrids were obtained from cross combinations of R.laxaבKardinal’ ,R.laxaבSolidor’ and R.laxaבYuzen’,respectively.The karyotypes of parents and their interspecific hybrids were analyzed using traditional squashing method.The results showed that 15 F₁ hybrids were triploid,except that one of the hybrids between R.laxa and ‘Kardinal’ was diploid.The karyotype formula of R.laxa was 12m+2sm belonging to 1A.Karyotype formulas of ‘Kardinal’,‘Solidor’,‘Yuzen’ were 28m,28m,24m（2SAT）+4sm,respectively,of which belonged to 1A,1B and 2B.Karyotype formulas of hybrids of R.laxaבKardinal’ included 1A,1B and 2A.Karyotype formulas of hybrids of R.laxaבSolidor’ included 1A and 1B.Karyotype formulas of hybrids of ‘Yuzen’×R.laxa included 1A,1B and 2B.According to the karyotype characters,triploid F₁ hybrids were true progeny,however,the hybrid authenticity identification of diploid F₁ hybrids could not be confirmed.