Abstract: Existing research has pointed out the importance of integrating organizational ambidexterity into international business, but doesn’t uncover the question whether firms should and are able to implement exploring and exploiting internationalization simultaneously, and under what conditions is more beneficial. This paper integrates organizational ambidexterity and international business to define the concept of balance and combined dimensions of international ambidexterity, and tests their impact on innovation performance and the moderating effect of internal and external competitive intensity. Based on survey data of 227 Chinese manufacturing firms, we find that balance and combined dimensions of international ambidexterity both positively influence innovation performance, internal competitive intensity negatively and external competitive intensity positively moderate their relationships respectively. This paper supports the international ambidexterity theory and contributes to the boundary conditions.