The phase diagram of Co-rich Sm-Co-Ti system was obtained by X-ray diffraction analysis and magnetic measurement. It was found that there exist three series of compounds, SmCo7-xTix, Sm2Co17-xTix and SmCo12-x Tix. The formation ranges for these three series are 0.32≤x≤0.54, 0≤x≤1.13 and 1.45≤x≤1.95, respectively. The 3∶29 phase was not found after annealing Sm9.31Co90-xTix (3≤x≤15) prepared with an excess Sm of 15%, 20% and 25% added, at temperatures ranging from 1303 to 1403 K. It was also found that the Curie temperatures TC and saturation magnetization Ms decrease with increasing Ti content for both SmCo12-xTix and Sm2Co17-xTix compounds. Below TC, the uniaxial and planar anisotropies were observed for Sm2Co17-xTix and SmCo12-xTix compounds, respectively. The anisotropy fields Ba measured at 1.5 K for both SmCo12-xTix and Sm2Co17-xTixcompounds as a function of Ti content x exhibits a peak at certain compositions, which is thought to be associated with the preferential substitution of Ti for Co.