Starch is one of the richest natural polymers with low-cost,non-toxic and biodegradable,but is seldom directly used as corrosion inhibitor due to its poor inhibitive ability and low water solubility.To solve this problem,cassava starch-acryl amide graft copolymer (CS-AAGC) was prepared through grafting acryl amide (AA) with cassava starch (CS),and it was firstly examined as an efficient inhibitor for 1060 alu-minum in 1.0 mol·L-1 H3PO4 media.The adsorption behavior of CS-AAGC and its electrochemical mech-anism were investigated by weight loss and electrochemical methods.Additionally,the inhibited aluminum surface was fully characterized by a series of SEM,AFM,contact angle measurements and XPS.Results confirm that CS-AAGC performs better inhibitive ability than CS,AA or CS/AA mixture,and the maximum inhibition efficiency of 1.0g·L-1 CS-AAGC is 90.6％ at 20 ℃.CS-AAGC acts as a mixed-type inhibitor while mainly retards the anodic reaction.EIS has three time constants,and the polarization resistance is significantly increased in the presence of CS-AAGC.The micrograph of inhibited aluminum surface is of hydrophobic nature with low surface roughness and little corrosion degree.