This research aimed to describe and analyze the creative thinking process of primary school students in solving open-ended problems in terms of mathematical ability. This research used descriptive-qualitative method. The creative thinking process observed in this research subject activity in the preparatory, incubation, ilimination and verification phases. Subjects in this research are 3 people, they are: 1 student with high, medium, and low math skills. The instruments used in this research are math ability test (TKM), task of problem solving (TMM), and interview guide. To test credibility of the data used time triangulation. The results showed that students with high, medium, and low math skills went through the creative thinking phase with unequal steps. From the results that have been analyzed it was obtained that to get a result of creative problem solving then it takes time for students to settle the problem in order to get the best solution. Therefore it is better for teachers to assign tasks to students to do at home with problems that are not routine to provoke student’s creative thinking so they have time to settle the problem and can provide the best solution.