Heart of Dragon (Chinese: ; Cantonese Yale: Long De Xin) is a 1985 Hong Kong action film directed by Sammo Hung, assisted by Fruit Chan. Sammo stars as Danny / Do-do, a man with a mental illness, cared for by his brother Tad, played by co-star Jackie Chan. Yuen Biao assisted Hung with the action choreography, though did not appear in the film.
It is also known by the titles Heart of the Dragon, The First Mission and Powerman III.
The final scenes were filmed on the building site that was later to become the Regal Riverside Hotel in Sha Tin.