The present invention provides an amine-based polymer, a preparation process thereof and use thereof. The amine-based polymer of the present invention is characterized in that said amine-based polymer contains a polymer main chain, and a structure represented by formula (I) is attached onto the polymer main chain, and said structure is attached to the polymer main chain via an attaching end present in at least one of Group G, Group G′ and Group A in the structure, wherein each of the groups is defined as in the description. The amine-based polymer of the present invention is suitably used as a detergent, particularly suitably used as a fuel detergent. The amine-based polymer of the present invention is useful as a fuel detergent, and has an extraordinarily excellent detergency and dispersion properties.