Recent decades have witnessed a sharp increase in the amount of household waste generation worldwide, which inevitably brings about serious environmental problems and exposes sustainable urbanism to overwhelming challenges. China, as the most rapidly industrialised and populous country, is undeniably the largest household waste producer, generating about 200 million tonnes of household waste per year. Since the 21st century, China has been promoting to separate and collect household waste at source, however, household waste sourceseparated collection programmes in China are still in the initial stage and there is little literature on household waste management in the research context of China. To fill this gap in literature and to provide pragmatic implications for policymakers in Nanjing, a 20-person pilot interview and a self-report questionnaire survey with a sample size of 449 are conducted in Gulou District, Nanjing, adopting the TPB+ model I construct. The results of data analysis show that the 10 policy-related factors in the TPB+ model all have significant impacts on Nanjing residents' household waste source separated collection behaviour. Among them, environmental knowledge and awareness towards environmental problems, social/community atmosphere, publicity, policy clarity, accessibility to facilities serve as the five best predictors, suggesting that attitudes, subjective norms, perceived behavioural control and normal norms are significant determinants of Nanjing residents' household waste source-separated collection behaviour. By contrast, the predictive validity of situational factors is relatively mild. Based on the findings, this dissertation further provides several relevant implications for the Nanjing government.