Abstract: Disclosed herein is a method for determining whether a subject has or is at risk of developing colorectal cancer with an ex vivo biological sample isolated from the subject. The method comprises: determining the levels of at least two target proteins with the aid of mass spectrometry, in which the at least two target proteins are selected from the group consisting of ADAM10, CD59, and TSPAN9; and assessing whether the subject has or is at risk of developing the colorectal cancer based on the levels of the at least two target proteins. The present method may serve as a potential means for diagnosing and predicting the incidence of colorectal cancer, and the subject in need thereof could receive a suitable therapeutic regimen in time in accordance with the diagnostic results produced by the present method.