This study aims to investigate the relationship between the determination of dopamine level by high performance liquid chromatography (HPLC) with electrochemical detection (ECD) and the detection of dopamine transporter (DAT) counts using autoradiography with DAT image agent [99mTc]TRODAT-1. For striatal lesions, pretreatment of 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle shows that autoradiogaphic labeling of striatum region is reduced to near-background level. Using HPLC with ECD, unilateral 6-OHDA treatment is associated with significant (p < 0. 0002) reductions of dopamine levels. For the striatum of the 6-OHDA-lesioned side, dopamine content and DAT counts are reduced to 97% and 90%, respectively. Thus, our observation indicates a potential of using [99mTc]TRODAT-1 for the evaluation of animal DAT.