Abstract: A possible mechanism responsible for the exceptional rainfall over Taiwan by Typhoon Morakot (2009) (named Morakot simply here after) was explored by the means of the investigation of the binary typhoon vortices (BTV) interaction. The analysis of the three-dimensional thermal-dynamic structure revealed that there is substantial moisture, energy transport from Typhoon Goni (2009) to Morakot. The inherent correlation between the two vortex respective development and decay is also obvious, indicating aoccurrence of mutually rotating. The dynamic vertical structure of the two vortexes presents an opposite tendency, namely, the intensity of Typhoon Goni vortex becomes weaker and asymmetric with the time elapsed, which is in contrast to the continuous development of "Morakot" during the period of the BTV interaction. However, the horizontal structure of energy and potential vorticity distribution of the two vortexes is characterized by obvious connecting body transportation. A significant moisture transport channel from Typhoon Goni to Morakot can be deduced from the further analysis of the correlation between the satellite blackbody temperature (TBB) over the Taiwan areas and the moisture column flux around its surrounding areas. Using the trajectories model Flexpart coupling with a mesoscale weather forecasting model WRF, we reproduced this moisture transport pathway by the backward tracking of majority of air parcels initialized over the cores of Goni. In addition, the numerical simulation experiments with the Goni vortex being removed or not further confirmed that the moisture and energy transportation from Goni is one of the key factors for the development and maintenance of Morakot. Based on the above data diagnosis, trajectory analysis and numerical simulation, a three-dimensional image of BTV interaction is provided to describe the energy, moisture transport of BTV, and the development and decay of BTV.