The invention discloses a method for synthesizing 
rosin or allyl ester which is 
rosin derivative, which comprises following steps: dissolving one of the 
rosin or the rosin derivative in aprotic 
solvent, adding acylate-chloridized agent, heating to enable 
reaction temperature to be in 0-85 DEG C, reacting for 0.5-5 hours, acylate-chlorizating carboxy group in the rosin or the rosin derivative, adding acid binding agent, 
polymerization inhibitor and 
allyl alcohol into the 
reaction product of the first step, reacting under 10-80 DEG C for 2-5 hours, removing the aprotic 
solvent, and obtaining the rosin or the rosin derivative, namely, allyl ester, wherein the using amount of the acid binding agent is 100-150% of the 
molar weight of carboxy group in the rosin or the rosin derivative and the using amount of the 
polymerization inhibitor is 1% of the 
allyl alcohol. Synthetical rosin or rosin derivative, namely, allyl ester, can generate 
radical polymerization and can be applied in the fields of 
coating material, cementing compound, 
printing ink, paper making and the like. The method has high technical efficiency and good product stability.