The present invention relates to a process for producing a hydroxy amino polymer comprising the steps: a) Reaction of an H functional starter compound bearing at least one Zerewitinoff active H atom with an unsaturated, cyclical carboxylic acid anhydride and at least one alkylene oxide compound for obtaining a prepolymer bearing hydroxyl groups, b) Addition of a primary amine and/or of ammonia to the double bond(s) of the prepolymer bearing hydroxyl groups obtained according to step a) for obtaining the hydroxy amino polymer, wherein the ratio of added amino groups to hydroxyl groups in a hydroxy amino polymer is at least 0.6. Furthermore, the invention relates to a hydroxy amino polymer, which can be achieved according to this process as well as a polyurea/polyurethane system, which contains such a hydroxy amino polymer.