A paper coating composition which comprises as a binder a latex of a copolymer (referred to hereinafter the particle A) consisting of (a) 20 to 80% by weight of an aliphatic conjugated diene monomer unit, (b) 0.5 to 10% by weight of an ethylenically unsaturated carboxylic acid monomer unit and (c) 20 to 79.5% by weight of a unit of another monomer copolymerizable with the above components (a) and (b) and having two glass transition points in the range of from -100.degree. C. to 50.degree. C. the difference between the two transition points being at least 5.degree. C.