Criticisms addressed to the mechanism for resolving disputes between foreign investors and host countries, i.e. investment arbitration, have led to various proposals and attempts to find optimal reform options. Within the framework of UNCITRAL's Working Group III, since 2017 proposols from various stakeholder have been considered. This paper analyzes the main objections to the dominant investor/state dispute settlement system, as well as the most important reform options, which appear in the literature and practice of international organizations, primarily UNCITRAL. Although this process is still ongoing, it is evident that, on the one hand, there is a plurality of different interests and proposals of the main actors of international investment law, while, on the other hand, there is a wider consensus on the necessity of certain reforms in order to establish and strengthen consistency, uniformity and predictability of arbitration decisions. Certain reforms are already being implemented in practice through new investment agreements.