Abstract: Interspecific hybridization among Syringa had been studied from 1988 t o 1989 in the 3th nursery, Harbin. The result showed: (1) There was big affinity difference among the different crossing groups. 18 crossing groups were researched, 5 of them got normal F1 hybrids seeds, but their fruit setting percentage was different. After reciprocal crosses of S. alba and S. vulgaris, t he fruit setting percentage of F1 hybrids all surpassed 86 per cent and displaying highe r affinity, however in S. vulgaris var. plena (female parent) and S. alba (male parent), the fruit setting percentage of F1 hybrids only reached 8 per cent, affinity dropped obviously. (2) The interspecific crossing in Syringa can succeed, with F1 hybrids growth well, flower colour variability abundant and inheritance on petal stronger. Some new cultivars according with the breeding goal had been found.

Key words: Syringa, Crossbreeding, Flower colour, Inheritance on petal, Cultivar