Vertical product differentiation and horizontal product differentiation have long been recognized as key factors of firms' competition. Ferreira and Thisse (1996) shows that when two firms compete in both horizontal product differentiation and vertical product differentiation, and there's no price discrimination, subgame perfect Nash equilibria have the property that the extent of vertical product differentiation negatively related to the degree of horizontal product differentiation. The present paper shows that, in an oligopoly market, instead of single price competition, when firms compete with discriminatory pricing, the relation between vertical and horizontal product differentiation is determined by the order of entry. When firms choose location simultaneously, the extent horizontal differentiation is unrelated to the extent of vertical differentiation, and when firms enter sequentially, the extent of vertical product differentiation might positively relate to the degree of horizontal product differentiation.