In this paper, global optimal tracking control for multi-input-multi-output systems using adjoining cell mapping technology is studied. An adaptive criterion is first proposed to improve the existing adjoining cell mapping method for optimal control. The criterion can judge the availability of mappings from different pre-image cells to their adjoining image cells adaptively, and help to build mapping database with the minimal loss of useful mapping information. An accessible and efficient backward search strategy to obtain global optimal control solution is also advanced. Then, a subdivision strategy for adjoining cell mapping to solve optimal tracking control problems for multi-input-multi-output systems is introduced. Finally, three examples illustrate the performance of the adaptive criterion and subdivision strategy. The adjoining cell mapping method for optimal control is greatly improved and the proposed subdivision strategy offers an efficient numerical method with general applicability to solve global optimal tracking control problems for nonlinear multi-input-multi-output systems.