The aim of the study was to describe and provide information about the frequency of using code-mixing in the teaching and learning process of English through online classes, the types of code-mixing that the lecturer applied, and the
kind of function occurs through code-mixing. The design of this research is a descriptive study. The participants of this research were English lecturers who teach in the fifth semester to English Education Program students of IKIP PGRI
Pontianak. In collecting the data, the researcher recording, interviews. The research finding above showed that there showed the frequency of utterances that have total utterances of the speech is 146. The utterances are divided into 3 groups code-mixing, full first language, and full foreign language. Furthermore, the result of the table above showed that there were 110 utterances or speech using code�mixing in the process of teaching-learning through an online class, 36 utterances using a full first language, and 0 utterances using a full foreign language. It was found that the frequency of utterances of the speech had 75% code mixed, 25% used full first language which means Bahasa Indonesia, and 0% used full foreign language or English. This means that English lecturers at IKIP PGRI Pontianak,
especially those who teach in the fifth semester of the English Education study program, still often use language mixing in conveying material and interacting in the classroom.

Keywords: Code Mixing, English Lecturer, Descriptive Research, Descriptive Statistical Analysis.