Abstract: Based on the results of previous study,four novel curcumin pyrimidinone derivatives were designed and synthesized.The structures of the new compounds were identified by IR,1H NMR and MS.The acaricidal assay results showed that all four derivatives exhibited higher acaricidal potency than the parent compound. The 48 h LC50 values of 4,6-bis pyrimidin-2(1H)- one (3a) with the highest acaricidal potency were 487.5 and 200.3 mg/L to Tetranychus cinnabarinus and Panoychus cotri,respectively.The acaricidal potency of derivatives 3a was about four fold higher than that of curcumin against T.cinnabarinus and P.cotri.Moveover the 72 h LC50 values of 3a was 40.7 mg/L to T.cinnabarinus,which exhibited about fourteen fold higher acaricidal potency than that of curcumin.