This study aims to find out: (1) the effectiveness of LKPD mobile learning model problem-based learning on environmental change material used to increase the learning interest of grade X high school students; (2) the effectiveness of LKPD mobile learning model problem-based learning on environmental change material used to improve critical thinking of grade X high school students. This type of research is quasi-experimental with a pre-test design and post-test control group design. The limited trial subjects in this study were 34 grade X students of Senior Hight School 1 Ngabang. The field test subjects consisted of 36 experimental class students and 36 students for the control class in grade X of Senior Hight School 1 Ngabang. Data collection used several instruments, namely interviews, needs analysis questionnaires, assessment questionnaires for material experts, media expert assessment questionnaires, RPP expert assessment questionnaires, syllabus expert assessment questionnaires, biology teacher assessment questionnaires, student response questionnaires, learning interest questionnaires, critical thinking test sheets. Data analysis techniques use the normality test, homogeneity test, T-test, Mann-Whitney test, and n-gain score. The results showed that: (1) LKPD mobile learning model problem-based learning is effective in increasing students' interest in learning. The increase in interest in learning according to the n-gain score that occurred in the experimental class achieved a score of 0.7 in the high category, and (2) LKPD mobile learning problem-based learning model is effective in improving students' critical thinking. The increase in critical thinking according to the n-gain score that occurred in the experimental class achieved a score of 0.8 in the high category.