Abstract. In this paper we o¤er criteria for property (A) and the oscillation of the third-order nonlinear functional di¤erential equation with mixed arguments ½aðtÞ½x 0 ðtÞ g 00 þ qðtÞ f ðx½tðtÞÞ þ pðtÞhðx½sðtÞÞ ¼ 0, where Ð y a À1=g ðsÞds ¼ y. We deduce properties of the studied equations by establishing new comparison theorems so that property (A) and the oscillation are resulted from the oscillation of a set of the first order equations.