Within the scope of this project supported by a grant from the Fritz-Thyssen-Stiftung a corporate microsimulation model (ZEW TaxCoMM) will be developed for the ex-ante-evaluation of corporate tax reforms. In particular, the model will be capable to account for behavioural responses of economic agents to a change in tax incentives. In contrast to other models a micro-based approach is able to account for the heterogeneity at the firm-level when calculating effective tax burden measures. Moreover, due to its explicit simulation of behavioural firm responses it is able to evaluate reform consequences beyond mere first-round effects.