251 senior middle school (Grade 11) students were tested on the Chinese Group Embedded Figures Test and Dynamic Problems Test. A 2 (cognitive style) x 2 (sex) analysis of variance indicated a nonsignificant effect with respect to cognitive style in solving easier Dynamics problems but a main significant effect in solving complex Dynamics problems. Multiple comparisons (post hoc t tests) indicated that cognitive style is a significant factor among boys but not girls. The difference between Field-independent students and Field-dependent students in solving complex Dynamics problems may be that the former students more easily form a clear map of motion than the latter students.