This study was aimed to describe how the learning process cas be done, observe the science process skills of students and analyse the student’s response to the problem based learning model. It used descriptive quantitative method by pre-experimental design research type, and adopted one group pre-test post-test design. The study showed that: (1) The achievement on learning process of the problem based learning was effective, with increasing score from the first meeting to the second meeting, it was 3.5 (criterion is very good) to 3.6 (very good criterion). (2) The application of the learning model based on a material issue of environmental pollution can improve science process skills are characterized by the calculation of the N-Gain test showed an increase for every aspect of science process skills. The difference results between pre-test and post-test is significant, it was proved by the t-test obtained t (6,69)> t table (1,70) with significance level α = 0.05. (3) Students responded well to all learning process by applying learning model based on the problem, with the percentage of students who gave a positive answer is 91%. Keywords: Problem Based Learning, Science Process Skills.