Titanium alloy is widely used in aerospace and aircraft industries but it is a kind of difficult-to-cut material. In this paper, wet grinding and dry grinding of titanium alloy Ti-6Al-4V using green silicon carbide wheel were investigated. The specific tangential force and force ratio were calculated and surface roughness of machined surfaces was measured. The morphology of machined surface were observed by SEM. The experimental results showed that the specific tangential forces were big. The depth of cutting has greater influence on surface roughness than workpiece speed. The surface roughness of wet grinding was better than dry grinding. Micro cracks were observed on wet grinding. The main reason is the high temperature and quenching cracking.