This research aimed to detect the effectiveness of a proposed training program in mathematical patterns to develop mathematical thinking of female math teachers in second cycle (5-10) basic education schools in Sultanate of Oman. A training program in mathematical patterns was designed to focus on a set of mathematical ideas, knowledge and skills in order to deepen mathematical understanding and development of mathematical thinking. This study used a mathematical thinking test was prepared by the researcher. The validity and reliability of the test has been verified. The research sample was consisted of (27) teachers of the second cycle (5-10) basic education schools in the Directorate General of Education in Governorate of Muscat in Sultanate of Oman. The research was following the design of one experimental group with pre- post tests. The teachers were trained on the program and their pre and post performance was measured by the mathematical thinking test. For testing the research hypothesis data was analyzed by paired samples T-test. The research showed the following results: There is a statistically significant difference at the level of significance (a = 0,05) between the mean scores of teachers in the pre and post application of their grades in the mathematical thinking teșt as a whole in favor of posttest. ☆ There is a statistically significant difference at the level of significance (a = 0,05) between the mean scores of teachers in the pre and post application of their grades in the skills (deduction, induction, intuitive thinking, use of symbols, and logical thinking) separately in favor of posttest. This research concluded with several recommendations according to the research results such as taking advantage of the training program in mathematical patterns in professional development programs for teachers, training teachers on topics related to mathematical thinking, and the ways to gain its skills. Further relevant studies and researchs were suggested to be done.