In this paper, the step-duration-orographic-intensification-factor (SDOIF) method is adopted to study the transposition of Taiwan Morakot storm over Hong Kong based on 66 stations of Taiwan with historical hourly data, storm observations during the period of Morakot storm invasion of Taiwan (2009.8.8-10) at 251 ground stations over Taiwan, 65 Hong Kong stations with historical data length more than 18 -year and 3 stations from Guangdong (Xili, Shiyan and Shenzhen stations). By using the SDOIF method, the maximum 24h rainfall of Morakot can be separated into the convergence component and the orographic component; a generalized convergence isohyetal pattern for the Taiwan Island based on the Morakot convergence components can be derived; transpose this generalized convergence isohyetal pattern onto the corresponding SDOIF of Hong Kong; then the embryonic PMP distribution can be obtained. It is found that the orographic intensified the maximum 24h rainfall of Morakot by 45%; the maximum (1230.2 mm) of the derived embryonic PMP distribution over Hong Kong located the same area as the storm center based on historical observations.