Abstract: High performance liquid chromatography(HPLC)was employed to determine the CoQ10 in brown rice with different genotype.The testing methodology was optimized in the meantime.Content of CoQ10 in 100 varieties(including restore lines and germplasm resources of the rice)was determined by using HPLC.The contents ranged from 0.30?0.03 mgkg-1 to 5.36?0.04 mgkg-1 indicating very significant differences of CoQ10 content existing among the various brown rice varieties.The restore line 4B233 had the highest content of CoQ10(i.e.,5.36?0.04 mgkg-1),which was 178.67 times greater than the lowest.