There is provided a rubber composition for a tire tread having a remained despersibility of reinforcing agents without increased rubber hardness, an improved performance on snow and ice road, and an improved abrasion resistance, and inhibited from increasing in hardness or inhibited from increasing in hardness with the passage of time. A rubber composition for a tire tread, which comprises (a) a diene rubber, (b) glass fibers, (c) a reinforcing agent, and 1 to 15 parts by weight of (d-1) inorganic powders having a Mohs hardness of less than 6.5 and an average particle-size of less than 25 .mu.m and/or (d-2) silicone rubber powders based on 100 parts by weight of the diene rubber.