This paper describes the preliminary design of the steady state tokamak reactor (SSTR) blanket cooled by a mixture of helium gas and fine solid particles. Light yet highly heat resistant material, titanium aluminide (TiAl), is used as structural material. Thickness of tritium breeding blanket using lithiated ceramics and beryllium neutron multiplier is minimized and high-temperature and non-breeding shield blanket is installed to enhance blanket energy multiplication. It is found that TiAl is advantageous in radioactive waste management because the contact dose rate of TiAl first wall attenuates rapidly. The gas-particulate mixture coolant lowers the helium pressure to 5 MPa and reduces the volumetric flow rate when compared to a pure helium-cooled blanket. The net thermal efficiency larger than 40 % can be achieved with the outlet coolant temperature of 700°C.