Abstract: The coatings was prepared using the modification of cardanol by rosin, and its performance was studied. The mechanism of rosin modified cardanol and effect of rosin dosage on curing rate of coating were analyzed by FT-IR. The results showed that the phenolic hydroxyl of cardanol and the carboxylic acid of rosin were esterified during the heating process, and the unsaturated rosin structure and the unsaturated side chain of cardanol were oxidized crosslinking reaction. With the increase of rosin dosage, the curing rate of cardanol was increased. When the rosin dosage(by cardanol quality) was 10%, the bio-based rosin modified cardanol coating with high gloss and good comprehensive properties could be obtained by curing at 150 ℃ after 24 h with 5% cobalt naphthenate as catalyst. Its gloss was 115, adhesion level was 1, pencil hardness was 2H, the impact strength was 35 kg/cm, and the flexibility was 1 mm.