To provide a method for recovering lithium in high yield from a polymerization solution formed by polymerizing polyarylene sulfide using lithium sulfide as a sulfur carrier and containing lithium chloride.

In the method for recovering lithium as the crystal of lithium hydroxide by adding an alkali metal hydroxide containing hydroxide ion having moles equal to or above that of lithium ion into the polymerization solution of polyarylene sulfide (after the separation of the polymer), the recovery of lithium is improved by reacting the solution containing lithium chloride while heating and dehydrating.