The Co-Current reactor gasifier is a promising technique, owing to its good performance and less residue content. Even though it can be used only for low moisture feedstock, it is needed improvement by incorporating modifications in the design of reactor, feeding system, air supply system, preheating air or feedstock, discharge system, recirculation technique, and co-gasification. Many of the researchers found that various improvement methods have been done to improve the performance of the gasifier at different operating condition. Therefore, in this paper a detailed review has been made to study about that developments of Co-Current gasifier and their effects on the performance of the gasifier. Further to improve the performance a suitable method for the gasifier is identified. A comparision with various methods reveals that design modification showed better performance, higher producer gas yield and less pollution. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.