The objective and outcome of transactions are resource allocation, closely related to market competition. Intellectual property transactions may be related to horizontal competition and may also affect vertical competition. In either case, if intellectual property right holders have sufficient bargaining power, they may have the motives to abuse their market position, seeking to exclude or restrict competition in relevant markets through transaction arrangements. Therefore, antitrust issues shall not be ignored in the analysis of intellectual property transactions. This chapter begins by analyzing potential monopolistic conducts in intellectual property transactions within the traditional analytical framework. It then reflects on the controversies arising from industrial development and antitrust practices. Finally, it discusses the breakthroughs and innovations that should be incorporated into the anti-trust regulations related to intellectual property transactions in the new economic era by deploying the new theories and methodological development in anti-trust analysis.