Abstract: This paper, through the analysis of naturally occurring English conversations, scrutinizes into the preference principles of person reference.The Preference Principle Model of Person Reference and three Principle Ranks are proposed.It is found that: 1) There are four preference principles underlying the choice of person reference forms, i.e.Preference Principle for Recognition, Preference Principle for Minimization, Preference Principle for Association, and Preference Principle for Situation; 2) There exist multiple relationships between the principles, i.e.competition, complementation, controlling, etc., and the choice of a specific reference form is the balanced outcome of the competing and controlling principles; 3) In the actual process of reference choice, the speaker will make a suitable choice among the principles based on the Principle Ranks when there are conflicts between the principles.