Abstract: PET can observe the biological behavior of cell at the molecular level.¹⁸F-FDG is the most widely used glucose metabolic imaging agent.3'-Deoxy-3'-¹⁸Ffluorothymidine(¹⁸F-FLT)is the most commonly used cell proliferation imaging agent.They both have been deeply researched in the diagnosis and staging of tumor.In recent years, researchers have paid more attention to monitoring the outcome of tumor therapy, especially to the relation between the uptake value variation of ¹⁸F-FDG, ¹⁸F-FLT before and during radiochemotherapy and tumor volume, cell proliferation, and cell cycle.This article was a research summary of the assessment of ¹⁸F-FDG and ¹⁸F-FLT in the outcome of cancer chemotherapy.