Anecessaryandsufficientconditionofregularityof(0,1,…,m-2,m)interpolationonthezerosof(1-x)Pn-1α,β(x)(α>-1,β≥-1)inamanageableformisestablished,wherePn-1α,β(x)standsforthe(n-1)thJacobipolynomial.Meanwhile,theexplicitrepresentationofthefundamentalpolynomialswhentheyexist,isgiven.