The potential application of a designed self-assembly peptide CH3CO-Pro-Thr-Phe-CysPhe-Lys-Phe-Glu-Pro-NH2(named as P1) as a carrier of 5-Fluorouracil(5-Fu) for controlled release in vitro was studied. 5-Fluorouracil(5-Fu) was selected as a representative anticancer drug due to its extensive use in treating digestive system cancer and breast cancer. The interaction between P1 and 5-Fu was detected by fluorescent quenching experiments and atomic force microscopy(AFM). The quenching mechanism of 5-Fu and P1 system was dynamic by performing fluorescent quenching experiments at different temperatures. The thermodynamic analysis demonstrated that the interaction between 5-Fu and P1 was hydrophobic interaction. The complexes prepared by the interaction between peptide and 5-Fu appeared as large granular particles of about 20 nm in height under AFM(denoted as5-Fu-P1), 24 times larger than the original 5-Fu particles. According to the results, an interaction model was proposed. Furthermore, 5-Fu-P1 complexes exhibited an efficient controlled release of 5-Fu in vitro. The research suggested that P1 might be a candidate carrier for drug delivery, providing a substitution agent for 5-Fu. Phe-Glu-Pro-NH2 (named as P1) as a carrier of 5-Fluorouracil (5-Fu) for controlled release in 5-Fluorouracil (5-Fu) was selected as a representative anticancer drug due to its extensive use in treating digestive system cancer and breast cancer. The interaction between P1 and 5-Fu was detected by fluorescent quenching experiments and atomic force The quenching mechanism of 5-Fu and P1 system was dynamic by performing fluorescent quenching experiments at different temperatures. The thermodynamic analysis demonstrated that the interaction between 5-Fu and P1 was hydrophobic interaction. The complexes prepared by the interaction between peptide and 5-Fu were as large granular particles of about 20 nm in height under AFM (denoted as 5-Fu-P1), 24 times larger than the original 5-Fu particles. As a result, an interaction model was proposed. , 5- Fu-Pl complexes an efficient controlled release of 5-Fu. The research suggested that P1 might be a candidate carrier for drug delivery, providing a substitution agent for 5-Fu.