This book provides an overview of the historical financial reforms and regulatory changes in China, highlighting the background to and causes of changes in the income structure of China's banks. It also investigates ongoing concerns with regard to banking diversification in China, and its consequences, amid the global trend of banks' shift to non-traditional businesses. Focusing on three critical aspects of bank-income diversification, namely the effects on profitability, risk level, and efficiency, it employs the concept of systemically important banks, which describes the scale and degree of influence a bank has in global and domestic financial markets. More importantly, rather than replicating techniques employed in the research on developed markets, it applies several improved methodologies to address bank diversification in the specific context created by China's unique institutional background and data characteristics, such as GMM-type threshold models and stochastic frontieranalysis with the within maximum likelihood estimation. Shedding new light on the current status of income diversification in the Chinese banking sector, this book is a valuable resource for readers in fields such as banking and financial stability. It will also help banking professionals and financial regulatory authorities to better understand the reform of China's financial industry and the future direction of banking.