The research used the mixed research method with the grounded theory approach. It examined the conditions for building cultural competence in teaching through an ethnographic study. Besides, the conceptualization of cultural competence in teaching and its impacts on interaction in classroom were developed and investigated through an experimental study in two phases (three months in 2011 and two months in 2013) in Lao Cai and Ha Giang provinces on the basis of video-analysis of the instructional periods supported by Transana software (version 2.51).