Abstract： Objective To evaluate the application value of quantitative immune fecal occult blood test (FOBT) in colonoscopy for the screening of colorectal cancer in health check-up participants. Methods The subjects were selected from July 2017 to June 2018 in the Health Management Center of the Second Affiliated Hospital of Suzhou University. The subjects were the healthy individuals who chose quantitative immune FOBT or chemical method plus immunogold double-method FOBT (referred to as"double-method FOBT"), excluding those who had interfering factors. Individuals with a positive result in primary screening were selected and conducted with colorectal cancer by colonoscopy. If the polyploidy lesions were observed during colonoscopy, the biopsy or excision was performed, and the pathological diagnosis was performed. The positive rate of primary screening, compliance rate of colonoscopy and pathological results of colonoscopy were compared between the two methods. Quantitative immunoassay FOBT was analyzed in different gender, age group, physical examination nature, positive rate of primary screening, compliance rate of colonoscopy and pathological results of colonoscopy. Results 18 728 people chose quantitative immunoassay FOBT and 6 212 people chose double-method FOBT at the same time. There was no significant difference in gender and age between the two groups (all P>0.05), which was comparable. The detection rate of quantitative immune FOBT was higher than double-method FOBT (74.62% vs 32.23%, P<0.001). The positive rate of quantitative immune FOBT in primary screening was lower than double-method FOBT (4.11% vs 5.34%, P=0.003). The colonoscopy screening rate in positive population by quantitative immune FOBT was higher than double-method FOBT (27.83% vs 13.08%, P=0.001). These differences were statistically significant. The detection rate of total lesions by colonoscopy was 71.88% in positive population by quantitative immune FOBT. It was 42.86% in double-method FOBT. There was no statistical difference between the two methods (P=0.05). The detection rates of quantitative immune FOBT were significantly different among different genders, ages and physical properties (all P<0.001). The detection rate was higher in males than in females (79.14% vs 68.75%). The detection rate was highest in the group between 40 and 59 years old (79.96%). The individual detection rate was higher than the group (90.08% vs 66.07%). The positive rates in primary screening were significantly different among different ages (P=0.001).It was highest in the group aged 60 or above (5.59%). The colonoscopy screening rate in positive population by quantitative immune FOBT was highest in the group aged 50 or above (36.96%). The detection rate of inflammatory lesions were significantly different among different ages (P<0.001). The detection rate of colorectal cancer in males was higher than in females (11.11% vs 0.00%, P=0.009). In addition, with the increasing of fecal occult blood value, the detection rate of cancer was increased (P=0.041). Conclusion The quantitative immune FOBT is an ideal non-invasive examination for early screening of colorectal cancer. It has important application values.