Solidification behaviors of IC10 alloy with different titanium content were investigated by isothermal solidification method. Volume percentage of liquid and precipitation temperature of primary MC type carbide, eutectic and secondary γ′ phase were investigated. The results showed that with the increase of Ti content in the alloy, the liquidus, solidus and MC carbide formation temperatures decreased, on the contrary, the formation of γ+γ′ eutectic and secondary γ′ increased. For the IC10 alloy with 1.5% titanium content, it is earlier for the interdendritic pools to be divided into the parts. At this condition, melted portion of the alloy resided during isothermal process. As a result, the castability of the IC10 with 1.5% titanium is thus the lowest.