Chapter 1 Overview of Financial Market Liquidity in China 1.1 Liquidity 1.2 Overview of China's financial market 1.3 Current status of liquidity research Chapter 2 Liquidity and Fractals Theory 2.1 Liquidity theory 2.2 Efficient market hypothesis 2.3 Fractals theory 2.4 Method system Chapter 3 Liquidity Measurement and Its Influencing Factors in China's Financial Market 3.1 Liquidity measurement 3.2 Influencing factors 3.3 Summary Chapter 4 Non-linear Characterization and Trend Identification of Liquidity in China's New OTC Stock Market 4.1 Introduction 4.2 Data description 4.3 Empirical research 4.4 Robustness test 4.5 Summary Chapter 5 The Nonlinear Characteristics Analysis and Trend Identification of Liquidity in Chinese Stock Index Futures Markets 5.1 Introduction 5.2 Data description 5.3 Empirical research 5.4 Robustness test 5.5 Summary …… Chapter 6 Non-Linear Volatilization Characteristics and Trend Identification of Liquidity in Chinese Crude Oil Futures Market Chapter 7 The Impact of Liquidity on Portfolio Selection Conclusions References