Abstract: To research an efficient method for total RNA extraction from Saccharomyces cerevisiae, haploid CEN.PK1and diploid CEN.PK2 as the object of study was used to study the new modified hot-acid-phenol method. The total RNA concentration of CEN.PK1 and CEN.PK2was 7.63 mg/mL and 3.77 mg/mL, OD260/280 was 2.10 and 2.04 and OD260/230 was 2.32 and 2.24, using the modified method by spectrophotometerdetermination．It is proved that the RNA was fit for the requirements of follow-up experiments in molecular biology by PCR and fluorescencequantitative PCR detection without DNA contamination compared with the Trizol method. The extraction time 1.5 hours is shorter than that ofconventional method 2.5 hours used and the modified method has the advantages of simple operation, high efficiency and high quality. Repeatedexperiments proved that this method can also be used to extract the total RNA amount of Saccharomyces cerevisiae and can be used for practicalapplications．