Intergeneric hybrids between Aspergillus niger and Perricillium ch~y.sop~um(Tyr ), hyperlipolytic enzyne-producing fungi, were obtained by nuclear transfer technique:. Optimal conditions for formation of intergeneric hybrids were investigated. Maximum production of protoplasts were obtainrd by 1% Novozym 234 at $30^{circ}C$ for 3 hrs and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6 M KC]. Frequencies of hybrid formation by nuclear transfer were $1.3{ imes}$10^{-3}$$</TEX> $-3.8{ imes}$10^{-3}$$</TEX>. From the chervation of genetic stability, conidial size, DNA content, ;md nuclear stain, it was suggested that their karyotypes are aneuploid. The hybrids showed 1.4-2.2 fold higher lipase activities than parental strains. It was strongly supported by results of this study that nuclear transfer technique is much more efficient in the formation of intergeneric hybrids than protoplast fusion and is very useful for the improvement of strains.