The conversation-analytic approach to second language acquisition （CA-SLA） is initiated by Kasper and the others（He, 2004; Kasper & Wagner, 2011; Markee, 2005; Mori, 2007; Seedhouse, 2005; Young & Miller, 2004）, trying to use the method of CA in SLA, with a focus on the social aspects of language acquisition. The analytical purpose of CA-SLA is to understand how L2 learners make use of language resources in interaction, create practice chances through interaction, and develop their L2 interactional competence, through the way of attending to the details of talk-and-other-conduct in interaction. CA-SLA, as a sharp tool probing into the social factors related to second language development, attracts a worldwide attention in the field of SLA and has been successfully applied in a series of empirical studies. This paper starts with an introduction of the background. It then describes the theoretical and methodological principles, as well as the recent development of CA-SLA, followed by a discussion of the values and limitations of this approach.