Language users not only communicate information, but construct social activity and social identity by using grammatical devices, which shows the interpersonal function, one of the three metafunctions of language proposed by Halliday.

As Left-wing literary trend of thought embodied modernity selection and contradiction in Chinese society in the 20th century, its emergence and development were closely related with the "social identity" and "regional culture" of its propagators, and with the historical map of revolutionary process.

As a social identity,the label shows his unpleasing shameful features,and influences his living situation.

The contemporary reading group can be surveyed from different aspects such as relationship, specialization level , social status, age stage, living region and history of existence.

After the set up of market economy system,the social status of workers and staff is changing into citizen.

There are lots of historical materials concerning occupations, social status and stratum in Wu slips unearthed at Zoumalou, Changsha.

In the transformation from status society to contract society,it excluded out of the new criminal law.

The paper is intended to analyze A Lost Lady by Willa Cather on the basis of the social identity theory and to discuss the characters and the themes of the novel.