The study is concerned with the code-mixing that consist of insertion, alternation and congruent lexicalization. The objectives of the research were to identify of code mixing in Mutiara Toba Movie and the dominant one type of code mixing. This reaserch was conducted by using qualitative method. The sources of the data were Mutiara Toba Movie and the data were 86 data of Mutiara Toba Movie. After analyzing, it was found that there were 86 data code mixing of Mutiara Toba Movie. The findings of this research were found that insertion is 74, alternationis 10, and congruent lexicalization is 2. Insertion 74 becomes the dominant type of code mixing inMutiara Toba Movie.