Abstract： Objective To detect the PML-RARα fusion gene expression of APL patients with FISH and fluorescent quantitative PCR and discuss the sensitivity and specificity of two techniques. Methods The detection of the PML-RARα fusion gene expression of 75 APL patients with FISH and fluorescent quantitative PCR were carried out simultaneously. Results Eighty eight patients of primary and relapse or remission phases were examinated and total conformity rate was 96.59 %. Fourteen primary patients were detected and conformity rate was 100 %. Seventy four relapse or remission patients were detected and conformity rate was 95.95 %. Stem cell essays were detected for six times and conformity rate was 100 %. Conclusion The sensitivity of FISH and fluorescent quantitative PCR is identical for primary APL patients and FISH is more sensitive. But the sensitivity of FISH is weaker than that of fluorescent quantitative PCR for detection of residue disease.