Abstract: The result of complex segregation analysis in 200 nuclear families with psoriasis vulgaris is reported in this paper.The made of inheritante of psoriasis was consistent with poaygenic hypothesis which postulated that psoriasis was detcrmined by more than one allele as well as environmental factors.The poIygenic heritabiiity was estimated at 0.63 in the complex segregation analysis.Falconer regression method Bras also used.An estimate of 0.70 for herit ability was obtained by the prevalence rates of the general population and the prohand's relatives.No significant difference was between the estimates diffierent methods.

Key words: Dsoriasis Segregation, anlysis Heritability