There are two theoretical bases that support that the extra-Party intellectuals are the subject of United Front work: 1) The United Front which lies in the working class, in fact, differs in sense from the United Front lying in the working class formed by Marx and some other persons. The reason why there is United Front in working class in new times mainly depends on the fact that the intellectuals join the working class. 2) There is United Front among the labors in socialist society. Intellectuals join the United Front as a labor group like workers and farmers, and as basic power and relying power in socialist society. Intellectuals belong to the first domain of the patriotic United Front in new period. There are three reasons why extra-Party intellectuals can be the subject of United Front: Firstly, intellectuals are a group with its own advantges. Secondly, intellectuals are a group which would play a more important role in the construction of Four Modernizations. Thirdly, it meets the aims such as caring of the special characteristic of the extra-Party intellectuals, carrying out the policy on extra-Party better, and fully arousing their zeal, initiative and creativeness.