To obtain a hair treatment composition exhibiting excellent masking effects on unpleasant odors derived from ammonia, an ammonium salt, monoethanolamine and a reducing agent, exhibiting high scent-lingering properties even when hair is washed after the treatment and having excellent fragrance stability with time.

This hair treatment composition comprises (A) at least one fragrant component selected from among 3,7-dimethyloctan-3-ol, 2,6-dimethyl-7-octan-2-ol, 1-phenylethyl alcohol, 3-methyl-5-phenyl-1-pentanol, o-t-butylcyclohexyl acetate, p-t-butylcyclohexyl acetate, 4-t-butylcyclohexanol, 2-n-heptylcyclopentanone, 4-(2,2,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one, and the like, and (B) at least one component selected from among ammonia, an ammonium salt, monoethanolamine and a reducing agent bearing sulfur atom.