This research aimed at describing the effectiveness of the local culture-based 7E learning cycle model in improving students' critical thinking skills in chemistry learning. It was an experimental research with post-test only control group design. The population was the eleventh-grade students of senior high schools in Singaraja, Indonesia. The sample included 111 students; 57 students as the experimental group and 54 students as the control group. The students in the experimental group learned through the local culture-based 7E learning cycle model, whereas the ones in the control group learned through the discovery learning model. The data on the students' critical thinking skills were collected through the critical thinking skills test. The data were analyzed through descriptive and inferential analysis, namely: Independent Sample T-Test for normal and homogeneous data, but Mann-Whitney U-Test for not normal and/or not homogeneous data. The results showed that the average score of students' critical thinking skills on the experimental and control groups were 64,5 and 55,3 respectively. The average score of the students' critical thinking skills on the experimental and control groups in the high-level school were 70.0 and 58.4, respectively, but in low-level school, they were 58.7 and 50.8 respectively.