Introduction: Nowadays, regarding the learners' needs and social conditions, it is obviously needed to revise and reconsider the traditional methods and approaches in teaching. The problem solving approach is one of the new ways in Teaching and learning process. This study aimed at studying and examining the effect of "problem-solving" approach on creative thinking of high school female students.
Methods: An experimental method is used for this research. In this research, 342 out of 3047 female-students from Sari high schools were randomly selected. These 342 students were divided into two groups (experimental and control) in which there were seven classrooms. The total number of students in every group was about 171. After testing them with Jamal Abedi creativity test, it was revealed that two groups were equal in creativity score. The tests were done through Requirements. The experimental group was taught by problem solving method for three months while the control group was taught by traditional method.
Results: The research results showed that using descriptive indices and t-test for the two independent sample groups in which problem solving teaching method was used in teaching processes had an effect on creativity level in comparison with traditional method used in the control group.
Conclusion: Considering the results of this study, the application of problem-solving teaching methods increased the creativity and its components (fluidity, expansion, originality and flexibility) in learners, therefore, it is recommended that students be encouraged to take classes on frequent responses on various topics (variability) and draw attention on different issues, and expand their analysis on elements in particular courses like art (expansion). To enhance the learner's mental flexibility and attention to various aspects, they are encouraged to provide a variety of responses.
Keywords: Critical Thinking; High School; Iran; Mazandaran; Sari; Students; Teaching Methods.