Objective To explore the reasons why colorectal cancer patients refuse to accept genetic screening associated with hereditary bowel cancer and to provide a basis for further measures to improve the rate of genetic and bowel cancer screening in patients and families.Methods Totally 14 patients first diagnosed of colorectal cancer from 3 Class Ⅲ Grade A hospitals in Guangzhou between August and December 2017 and refused to accept genetic screening associated with bowel cancer were selected by purposive sampling. The phenomenological method in qualitative studies were used for unstructured interview in these patients. The data were organized and analyzed with Colaizzi analysis.Results This study boiled down to 4 topics: lack of knowledge, avoidance of facts, strong psychological defense mechanism, lack of confidence in existing medical technologies, distrust on medical workers and worries about negative effects.Conclusions Medical and nursing workers shall explore further the reasons why the patients refuse to accept genetic screening, provide genetic counselling, improve the rate of genetic screening in high-risk patients, and improve the diagnosis rate of hereditary bowel cancer.