To provide a stable solution of a metal compound which is usable not only for preparation of a polyester by means of a direct esterification method but also for preparation of a polyester by means of an ester-exchanging method and does not cause precipitation of the metal compound even after a long time storage.

A method for preparing a solution of a metal compound to be added in a process of preparation of a polyester is characterized in that an alcohol-soluble metal compound is solubilized in a solvent containing 5 to 100 wt.% of a saturated monohydvic-alcohol.