This study intends to clarify syntactic problems concerning dangling topic construction in Mandarin Chinese by using probabilistic approaches. The relationship between the topic and the rest of the construction is often analyzed syntactically in studies of topic construction in Mandarin Chinese. However, dangling topic construction, wherein the topic in the construction seems to dangle, is not clarified by the syntactic approaches. Accordingly, previous studies had to implicitly make use of other approaches (such as pragmatics or semantic-pragmatics) to advance their arguments. The difficulty is that the concepts of pragmatics used in these studies are very vague and subjective. In order to tackle this problem, this paper explicitly computes the relation in dangling topic construction in Chinese using pointwise mutual information and Bayesian models. We also collected experiential data using human ratings of the acceptance degree for a set of dangling topic constructions. The result demonstrates that the pointwise mutual information and Bayesian model are well predicative of the data on the human rating of these dangling topic constructions. This approach is likely to shed more light on the notion of topic construction and to help in understanding how Chinese speakers comprehend and process sentences and come to understand their meaning. More importantly, this study creates a novel, effective and practical computational approach to sentence processing, syntactic analysis and pragmatics studies.