Potassium titanate is obtained which has a novel configuration, exhibits excellent wear resistance when incorporated in a friction material and shows an excellent reinforcement performance when incorporated in a resin composition. A manufacturing method of the potassium titanate, a friction material using the potassium titanate and a resin composition using the potassium titanate are also obtained. The potassium titanate is represented by K2TinO(2n+1) (n=4.0-11.0) and has the highest X-ray diffraction intensity peak (26) in the range of 11.0°-13.5° with its half width being not less than 0.5°.