<p>A polyether polyol composition which can be reacted with a polyisocyanate at a reduced rate and gives an isocyanate-terminated prepolymer excellent especially in storage stability. The polyether polyol composition comprises: a polyether polyol obtained by the ring-opening polymerization of an alkylene oxide in the presence of a composite metal cyanide complex catalyst; and at least one phosphoric acid compound comprising a phosphoric acid selected among orthophosphoric acid, polyphosphoric acid, and polymetaphosphoric acid and/or a partial ester of the phosphoric acid. It is characterized by containing the metal derived from the composite metal cyanide complex catalyst in an amount of 1 to 30 ppm of the polyether polyol and containing the phosphoric acid compound in an amount of 0.5 to 100 ppm of the polyether polyol.</p>
