The study purposes were: 1) To study current states and problems of relevant secondary students in developing mathematics learning management model for improving creative thinking, 2) To evaluate the effectiveness of model about: a) efficiency of learning process, b) comparisons of pretest and posttest on creative thinking and achievement of students, and c) comparison of creative thinking and achievement between experimental group and control group. The model was created and implemented with grade eight students of secondary schools, in Thailand, and compared with control group, provided in traditional approach. The research results were: Most of relevant teachers didn't concentrate in mathematics learning for improving creative thinking, and lacked using strategies to engage divergent thinking. The model was designed through methodology of R&D, which was composed of: 1) principles and theoretical concepts, 2) learning objectives, 3) learning process, 4) social system, 5) principles of response, 6) the support system. Whereas, the activities in learning process consisted of 1) engagement and understanding prior knowledge, 2) encountering problems with thoughtful thinking, 3) analyzing alternative and investigating solutions, 4) modifying of thinking patterns, 5) concluding and evaluating for creative thinking. The findings indicated that effectiveness of model based on achievement score was 76.25%, and based on creative thinking was 61.67%. The average posttest in learning achievement and creative thinking abilities of the experimental group were higher than pretest, and experimental group showed higher creative thinking than control group at the 0.01 level of significance.