To provide a method of removing impurities such as catalyst residue, particularly, impurities containing metals from a norbornene compound polymer hydrogenated substance solution in high removing efficiency without damaging the productivity, even in the case where the molecular weight of the polymer hydrogenated substance is high or the viscosity of the polymer solution is high.

In the method of purifying the norbornene compound polymer hydrogenated substance, an alcohol, water and a basic compound of an amount necessary to make the water basic are added to the norbornene compound polymer hydrogenated substance solution obtained by hydrogenating a norbornene compound polymer by using a homogeneous hydrogenation catalyst, to remove insoluble matter produced. Also, the norbornene compound polymer hydrogenated substance obtained by this purifying method and the molding material and molding made therefrom are provided.