Objective To study the accuracy and safety of oral mucosal exfoliated cell specimens used in the bedside rapid detection of MTHFR C677T genotype by using the fluorescent probe method.Methods The outpatients and inpatients with hypertension visited and admitted in the department of cardiovascular medicine of this hospital from January 2019 to September 2020 were selected.The plasma homocysteine (Hcy) level in all patients was detected in the laboratory,a total of 482 hypertensive patients with Hcy≥10 μmol/L were se-lected,and the oral mucosal cells and whole blood sample were collected in all patients,and the genotypes of the above specimens were detected by the oral mucosal exfoliative cell fluorescent probe method and whole blood sample contrast reagents.If the two test results were inconsistent,the "gold standard" Sanger sequen-cing method was used to detect the whole blood sample for the final determination of MTHFR C677T geno-type.The coincidence rate was compared between the two detection methods,and the probability of adverse e-vents during the samples collection was observed and recorded.The accuracy and safety of fluorescence probe method for detecting MTHFR C677T genotype in the patients with oral mucosa exfoliation was evaluated.Re-sults The oral mucosal exfoliated cell samples and whole blood samples from 482 hypertensive patients were successfully collected,and no obvious adverse reactions occurred during the sampling process.The incidence rate of total mutation of MTHFR C677T gene detected by the fluorescence probe method and contrast reagent all were 73.23％ (353/482),the coincidence rate of homozygous wild type (CC type) in MTHFR C677T gene detected by the two methods was 100.00％ (95％CI:97.11-100.00),which of heterozygous mutant type (CT type) was 99.14％ (95％CI:96.91-99.76),which of homozygous mutant type (TT type) was 99.17％(95％CI:95.47-99.85),the total coincident rate of MTHFR C677T genotype was 99.38％ (95％CI:98.19-99.79)and the detection results consistency Kappa value was 0.9902.Conclusion The detection of MTHFR C677T gene mutation in oral mucosal exfoliated cells by fluorescent probe method is simple with less invasion,moreover which is rapid,safe and accurate.