Clock gating analysis of a target circuit having a plurality of clock gates, involves the calculation of a clock gate function for each of the clock gates. The clock gate functions indicate an activation state of the clock gates and a combination of output values from sequential circuit elements in the target circuit are substituted into each of the clock gate functions to obtained clock gate function values. Combinations of the clock gate function values form individual clock gating states. Each clock gating state indicates an activation state of each of the local clocks, collectively. A table indicating correlations between the combinations of output values and the clock gating states is generated and from the conversion table, a group that includes all of the clock gating states possible is output.