▎ 摘　　要

NOVELTY - Contrast agent (I), is new. USE - The contrast agent intermediate is useful for preparing the contrast agent (claimed). ADVANTAGE - The contrast agent has high relaxation, good stability, and non-specificity. DETAILED DESCRIPTION - Contrast agent of formula (A-(B-R)n) (I), is new. A = graphene oxide or functional group-modified graphene oxide; R = gadolinium metal complex, formed by Ra and gadolinium metal complex molecules; B = bridging molecule, formed by bonding of chemical bonds with the graphene oxide surface, and bonding of chemical bonds with the gadolinium metal complexes; - = a bond; and n = greater than 1. INDEPENDENT CLAIMS are also included for: (1) preparing the contrast agent; (2) a contrast agent composition, comprising the contrast agent and a diluent; (3) angiography, comprising administering the contrast agent composition to a subject or a sample be imaged, and carrying out angiography; (4) medicine composition, comprising contrast agent as a drug carrier, an active ingredient loaded on the contrast agent, and a carrier; and (5) a contrast agent intermediate (II).