Particulate polymer composition capable of absorbing water and aqueous or serous liquids is prepared by surface-crosslinking a crosslinked polymer of an at least 25% neutralized ethylenically unsaturated acid group-containing monomer with a polyol in the presence of a cation at 150-300degreesC. Particulate polymer composition capable of absorbing water and aqueous or serous liquids is prepared from a polymer derived from 55-99.9 wt.% of an at least 25% neutralized ethylenically unsaturated acid group-containing monomer, 0.1-5 wt.% crosslinking agent, 0-40 wt.% ethylenically unsaturated comonomers and 0-30 wt.% water-soluble polymer by coating 100 parts by weight (pbw) of the polymer with an aqueous solution containing 0.01-5 pbw of a polyol and 0.001-1 pbw of a cation and heating to a crosslinking temperature of 150-300degreesC.