Abstract: The strong time constraints are the time constraints when the delay time of Control Data Flow Graph (CDFG) is not satisfied. In order to meet the strong time constraints, we propose an optimizing algorithm for CDFG. This algorithm takes advantages of the associativity and distributivity properties of arithmetic operations, rearranges the CDFG, and modifies the syntactical structure while preserving the semantic meaning. It focusses on the critical path of CDFG, where most of the transformations are attempted to decrease the length of the critical path and hence the length of resultant CDFG.