Community Question Answering portals like Yahoo! Answers have recently become a popular method for seeking information online. Users express their information need as questions for which other users generate potential answers. These questions are organized into pre-defined hierarchical categories to facilitate effective answering, hence Question Classification is an important aspect of these systems. In this paper we propose a novel system, CQC, for automatically classifying new questions into one of the hierarchical categories. Experiments conducted on large scale real data from Yahoo Answers! show that the proposed techniques are effective and outperform existing methods significantly. © 2011 ACM.