PURPOSE: To obtain a skin cosmetic imparting springiness and moist feeling to the skin, free from stickiness, slimy feeling and stretching feeling and having excellent protective effect by compounding a water-soluble partially deacetylated chitin having specific average molecular weight and deacetylation ratio.

CONSTITUTION: The objective skin cosmetic is produced by compounding 0.01-10wt.% (preferably 0.05-5wt.%) of a water-soluble partially deacetylated chitin having an average molecular weight of 100,000-1,000,000 and a deacetylation ratio of 40-60% [the compound of formula ((m) is ratio of N- acetyl-D-glucosamine residue to total residues and is 0.4-0. 6)]. The compound of formula has excellent adsorptivity to the skin and film-forming property, gives good feeling to the skin when compounded to a cosmetic and forms a cosmetic having extremely excellent skinprotecting effect. The compound of formula can be produced by hydrolyzing natural chitin with an aqueous solution of an alkali metal hydroxide of 5-50% concentration in homogeneous system at ≤50°C.