Abstract: Based on the computer and cognitive science theory, the representation of knowledge work process is a key point to increase the efficiency of knowledge work. Compared the representation of AI with that of KI, the shortage of these methods is analyzed. With the case analysis, a new method which describes the programming process using the mental operation (MO) is given. The confirmatory factor analysis demonstrates that knowledge work process can be represented using MO. The sample data support that concept collection entire model formed with nine essential factors of the MO can represent knowledge work processes. It provides a basic concept and an idea to increase the efficiency of knowledge work.