A dendritic polymer and a magnetic resonance imaging contrast agent employing the same. The magnetic resonance contrast agent includes the dendritic polymer according to the structure of SP-DZ-L)i)j or SP-DX-Z-L)i)j, wherein, S is cyclosilane moiety with j silicon oxygen residual groups, and j is not less than 2; P is CH2CH2Ol, and l is not less than 1; D is a C3-30 dendritic moiety having n oxygen residue, and n is not less than 3; X is C3-30 moiety having bi-functional groups; Z is a C3-20 moiety having a plurality of functional group; and L is a metal cation.