Introduction to Sociology, edited by Zheng Hangsheng, Renmin University of China Press, third edition, 2003.

A Course of Western Sociology Theory (Revised Edition) edited by Hou Junsheng, Nankai University Press, 2006.

Sociological Research Methods, published by Renmin University of China Press in 2005.

Introduction to Social Work, edited by Wang Sibin, Higher Education Press, second edition, 2006.

If you buy textbooks, you can order them online, or post them on Boya Forum or Huazhong Normal University Graduate Forum. Some seniors will sell them to you cheaply, and some seniors will give you notes for the postgraduate entrance examination.