Existing statistical methods for causality acquisition used one or more distribution characteristics of two events in the text. These major features are: (1) Co-Occurrence feature: the cause event and effect one may co-occur frequently; (2) Object-Sharing feature: the related two events may share a common participant; (3) Temporal feature: the cause event occur before (or simultaneously with) the effect event; (4) Distance feature: the two events may appear inside locally coherent text (in the same sentence particularly).