In four interspecies crossing combinations of grapevine (Seedling 108 x Muscat Hamburg, Muscat Hamburg x Seedling 108, S.V.I8315 x Muscat Hamburg and Muscat Hamburg x S.V.I2375) during three years period, resistance to important fungal diseases agents (Plasmopara viticola and Botrytis cinerea) were examined. Based on results of analysis of variance, for investigated characteristics, components of variance, coefficients of genetic and phenotypic variation and coefficient of heritability in a broader sense were calculated.