The aim of this research was to describe the implementation of problem solving model to improve students’ creative thinking skill. The four aspects of creative thinking skills which practiced in this research was fluency, flexibility, originality, and elaboration. This was a quantitative research that used one group pretest-posttest design. The subjects of this resarch were 25 students of XI MIPA 2 SMA Negeri 4 Sidoarjo. The data were collected by using tests. The data were analyzed with descriptive quantitative analysis. The results of this research show that the problem solving model was effective to improve students' thinking skills. The improvement of students' creative thinking skill viewed from the value of N-Gain has a range of values with the categories of medium and high. It was because the students active in the face of problems and seek for more innovative and diverse solutions. Based on these result, it was concluded that problem solving model was proper to improve students’ creative thinking skill on solubility and solubility product materials.