研究結果顯示，知識距離與溝通成效具有顯著負向關係；三項干擾知識距離對溝通成效之假設中，僅接收者外語嫻熟度對知識距離與溝通成效具顯著調節效果，正向干擾效果成立。研究證實，跨國合作者在進行溝通時，接收者外語嫺熟度越高，越能削弱知識距離對溝通成效之負向關係，提升溝通成效。 ;This empirical research aims to explore whether Knowledge Distance between giver and receiver affects Communication Effectiveness in international cooperation, to examine if Media Richness and Receiver’s Corporate Language Proficiency would moderate the relationship between Knowledge Distance and Communication Effectiveness, and to see if Receiver’s Corporate Language Proficiency would moderate Media Richness and further to moderate the relationship between Knowledge Distance and Communication Effectiveness. Survey via web-based and paper based questionnaires in Dec 2017, collected 336 valid questionnaires. With hierarchical regression analysis, the study examined the relationship between independent variable ‘Knowledge Distance’, dependent variable ‘Communication Effectiveness’, and Moderator ‘Media Richness’ and ‘Receiver’s Corporate Language Proficiency’. The results suggested that Knowledge Distance has negative influence on Communication Effectiveness, and which can be moderated by Receiver’s Corporate Language Proficiency. Better Language Proficiency brings better Communication Effectiveness diminishing the negative influence resulted from Knowledge Distance.