Objective: To investigate the difference of iron deposition pattern in subcortical nuclei between essential tremor(ET)and tremorpredominant Parkinsons disease(PDT).Methods: Fifty-three patients with ET,29 patients with PDT and 60 age-and gender-matched control subjects were enrolled in our study.The iron levels of substantia nigra(SN),globus pallidus(GP),putamen(PU),head of caudate(CA),and red nucleus(RN)were assayed by measuring bilateral average phase values using susceptibility-weighted phase imaging in a 3-tesla magnetic resonance system in all subjects.Serum ceruloplasmin level of all subjects was also determined.Results: ET patients showed significantly increased iron level represented by lowered bilateral average phase values in the bilateral SN and GP as compared with control subjects(p<0.01).Significant differences of nigral bilateral average phase values in PDT were found in SN(p<0.01),but not in other subcortical nuclei by co-ANOVA analysis adjusted for age,gender and serum ceruloplasmin levels when comparing with control group.There was significant difference of brain iron level in GP between ET patients and PDT patients(p<0.05).Significant correlation between the nigral bilateral average phase values and serum ceruloplasmin levels only in the PDT subgroup.Conclusions: Our study showed that ET was different from PDT patients in both the pattern of brain iron deposition and the relationship of brain iron deposition with the serum ceruloplasmin level.These findings suggest that ET may be a neurodegenerative disorder associated with brain iron accumulation.