Abstract: The deep development of China's reform and open door to the outside provides a rare chance to the great development of the Chinese theoretical economics. But the building of the theoretical economics system must first make clear the following important questions: what is the definition of economics and economist? Where is the foothold of economics? What is the difference between Marxist economics and the western economics? Whether is there a certain mutual supplement between the two different economics? For these questions, the author has made in this paper some demonstrations and proposed his own view points.