Abstract: The PET tracer 5-(¹¹Cmethyloxy)-L-tryptophan (5-¹¹CMTP) was prepared by nucleophilic fluorination and alkylation reaction via a two-step procedure in order to develop specific tumor probe. The biodistribution and microPET imaging of 5-¹¹CMTP were executed. The results unveiled that the overall radiochemical yield with no decay correction was (14.6 ± 7.2) %, the radiochemical purity was more than 95% and high uptake and long retention time of 5-¹¹CMTP in liver, kidney and blood were observed but low uptake in brain and muscle were found, furthermore, high uptake of 5-¹¹CMTP in tumor tissue was observed. It seems that 5-¹¹CMTP will be a potential amino acid tracer for tumors imaging with PET.