Abstract: Objective : To compare the sensitivity and specificity betweem FQ-PCR and RT-PCR in detecting mycgene and to discuss clinical application of the two methods in the diagnosis of breast carcinoma. Methods : Weused FQ-PCR and RT-PCR to detect myc mRNA expression in tissue samples from 139 patients with benignbreast disease or carcinoma and 40 health women. β₂-microprotein was used as the internal control. The re-sults were compared. Results : Using the standard that the expression of myc/β₂-microprotein was higher thanx^-+2s of normal controls, the positive ratio of breast carcinoma and benign disease were 41.0% and 0, respec-tively. Myc mRNA expression in the breast carcinoma group was higher than that in the benign breast diseasegroup (P<0.01). No significant difference was found in myc and myc/β₂-microprotein expression between thenormal controls and the benign breast disease group (P>0.05). No statistical significance was found in β₂-mi-croprotein expression among the three groups (P>0.05). The sensitivity and specificity of FQ-PCR for myc ex-pression were 41.0% and 82.2%, respectively. The sensitivity and specificity of RT-PCR for myc expressionwere 32.1% and 75.2%, respectively. Conclusion : The sensitivity and specificity of FQ-PCR for myc detectionwere higher than those of RT-PCR, with high precision and efficiency and low contamination. Gene expres-sion of myc can provide objective evidence for the diagnosis of breast carcinoma.