Children with poor reading comprehension skills often encounter great challenges in learning. Although there is a sizeable literature on the nature of poor reading comprehension in English (e.g., *Nation, 2005; Cain & Oakhill, 2008), little is known about Chinese poor comprehenders. The present study aims to fill in three important research gaps which are fundamental to understanding reading comprehension difficulties in Hong Kong Chinese children. Firstly, there is no research on specific comprehension difficulties in Chinese children. Specific comprehension difficulties refer to adequate word reading ability but unexpected difficulties in understanding the meaning of texts (around 7-10% of English children are identified; Clarke, Snowling, Truelove & Hulme, 2010). Whether specific poor comprehenders exist amongst Chinese children is not known. Secondly, few studies have investigated poor comprehension in Cantonese-speaking children. Spoken Cantonese has great linguistic discrepancy with written Chinese (which is close to Mandarin). Thus, reading comprehension can be particularly difficult for Cantonese-speaking children. Thirdly, past studies did not focus on how different text genres (e.g., narrative vs. expository texts), and how higher-order cognitive skills (such as world knowledge, inferencing and working memory) together with linguistic skills influence reading comprehension in Chinese poorcomprehenders.As such, the present study aims to investigate the cognitive and linguisticunderpinnings of reading comprehension in 300 Cantonese-speaking Hong Kong Chinesefourth graders. In study 1, we will examine what cognitive and linguistic skills predictindividual differences in reading comprehension. The effect of text genre (narrative vs.expository texts) will also be compared. In study 2, we will investigate the linguistic andcognitive predictors of Chinese poor comprehenders. Motivated by the Simple View ofReading, we will investigate if specific poor comprehenders exist amongst Chinese children. The cognitive and linguistic markers of Chinese poor reading comprehension will be derived from assessing seven core theoretically-motivated sets of cognitive and linguistic skills.Findings of this study are essential to understanding the nature of children’s reading comprehension difficulties in Chinese. This study will identify the underlying cognitive and linguistic mechanisms underpinning reading comprehension impairment, and in doing so, will also reveal how to identify poor comprehenders in the classroom, thus facilitating the development of comprehensive assessments and interventions for children with reading comprehension difficulties. Our findings will enhance our understanding of universal and language-specific factors related to reading comprehension difficulties. Importantly, we will extend current knowledge beyond English and other alphabetic languages to Chinese and children learning to read in Hong Kong.