A dendritic polymer and a magnetic resonance imaging contrast agent employing the same. The magnetic resonance contrast agent comprises a polymer according to the structure of or wherein, S is cyclosilane moiety with j silicon oxygen residual groups, and j is not less than 2； P is, and l is not less than 1； D is a C3-30 dendritic moiety having a plurality of oxygen residue； X is a moiety having bi-functional groups； Z is a C3-20 moiety having a plurality of functional group； L is a metal cation； and i is not less than 2.一種樹枝狀高分子及包含其之磁共振顯影造影劑，該樹枝狀高分子包含具有如以下結構之高分子化合物： 或 其中，S係為環矽烷，其具有j個Si－O－殘基；P係為 ，l係為大於或等於1之整數；D係為複個氧殘基(oxygen residue)之C3－30的多分枝基團；X係為具有雙官能基之基團；Z係為具有複數個官能基之C3~20的基團；L係為金屬陽離子；i係為不小於2之整數；以及，j係大於或等於2之整數。
