The present invention relates to a magnetic resonance imaging (MRI) contrast agent including a gadolinium complex, more particularly to a DO3A-tranexamic acid or its ester compound, which is represented by the Chemical Formula 1.A DO3A-tranexamic acid or its ester compound may be prepared according to the present invention and a gadolinium complex may be prepared using the compound. An MRI contrast agent including the gadolinium complex prepared according to the present invention as an active ingredient has higher relaxivity as compared to the currently commercially available contrast agent. In addition, the MRI contrast agent according to the present invention has bifunctionality of liver-specific and blood-pool contrasting effect. Accordingly, since the MRI contrast agent including the gadolinium complex according to the present invention satisfies the key properties required for a contrast agent for MRI, it can be widely used as an MRI contrast agent and can provide enhanced contrasting effect as compared to the existing contrast agent.
