Two-part allegorical sayings as an unique language form which exists pervasively in Chinese have evoked the interests of many scholars. The investigation of this linguistic phenomenon has many perspectives and dimensions. The paper illustrates the definition, classification and main characteristics of two-part allegorical sayings and aims to offer a cognitive linguistic interpretation of two-part allegorical sayings, exploring the cognitive mechanisms and processes of their comprehension. It is a fourth part of a series of research on Chinese idiom representation and comprehension. The paper further believes that the complex cognitive mechanisms, mental strategies and their interactions can lay a foundation for the experimental design of an ERP investigation.