Efficiency of 12.3% on solution-based Cu2ZnSn(SeS)4 (CZTSeS) solar cells was achieved by applying hybrid buffer layer with combination of In-based buffer and Cd-based buffer layers. Previously, the Voc boost by the hybrid buffer layer on Cu2ZnSnS4 (CZTS) and CZTSeS solar cells have been reported[1-2]. In this paper, the latest results and some analyses of the hybrid buffer for solution-based CZTSeS cells will be presented.