The present invention discloses 1,2-dithiolone compounds of the formula (I),wherein, A, Cy, R, R1, R2aand R2bhave the same meanings as defined in the description. The present invention further discloses methods for their preparation and the use of 1,2-dithiolone compounds of formula (I) and/or composition thereof for the protection of crops against undesired phytopathogenic microorganisms.本發明公開了式(I)的1,2-二硫醇酮化合物,其中,A、Cy、R、R1、R2a和R2b的定義如描述中所示。本發明進一步公開了它們的製備方法和式(I)的1,2-二硫醇酮化合物和/或其組合物用於保護作物免受有害的植物病原微生物侵擾的用途。