PURPOSE: To provide a pulsed air decoking method whereby decoking can be carried out in a short time; hence the shutdown time of a reaction apparatus can be reduced; combustion is maximized by automatic monitoring while damage to the apparatus is avoided; and troubles to operators can be limited.

CONSTITUTION: This method for decoking a coke-fouled hydrocarbon reaction pathway does not require the shutdown or cooling of a reaction apparatus and comprises the step of interrupting the hydrocarbon feed, the step of injecting a series of air pulses into a steam matrix for coke combustion for a period of time limited in duration until coke is removed, and the step of resuming the hydrocarbon feed.