Provided is hydroxyalkyl methylcellulose which can be dissolved at room temperature of 20 to 30.degree. C. and has high thermoreversible gel strength during thermoreversible gelation. More specifically, provided is water-soluble hydroxyalkyl methylcellulose having a molar substitution of hydroxyalkoxyl groups of 0.05 to 0.1 and a substitution degree of methoxyl groups of 1.6 to 1.9, wherein the hydroxyalkoxyl groups are classified into substituted hydroxyalkoxyl groups having hydroxyl groups of hydroxyalkoxyl groups substituted further with methoxyl groups and unsubstituted hydroxyalkoxyl groups having hydroxyl groups of hydroxyalkoxyl groups not further substituted; and a ratio (A/B) of a molar fraction (A) of the substituted hydroxyalkoxyl groups to a molar fraction (B) of unsubstituted hydroxyalkoxyl groups is 0.4 or greater.