This research discusses the complex relationship between voice and leadership emergence. Participants were composed of 312 undergraduates from Xi’an Jiaotong University. They were assigned to teams of 3 to 8 persons, with a total of 68 teams (without formal leaders). The results showed that different content of voice made different effects on leadership emergence.Supportive voice and constructive voice influenced significantly the emergence of individual leadership, while the influence of defensive voice and disruptive voice was insignificant. And we revealed the mechanism of voice content on leadership emergence from social process, and discussed the role of friendship networks.