A negative pressure dust collection structure aims to be used on a power tool which is coupled with an application tool operable in a working space surrounded by a dust collection hood. The dust collection hood includes at least one flow conduction vent communicating with an airflow duct through a negative pressure enhancing duct. The negative pressure enhancing duct has a negative pressure enhancing chamber communicating with the flow conduction vent. The negative pressure enhancing chamber is formed at a cross section shrunk gradually from the flow conduction vent towards the airflow duct to increase suction of the negative pressure enhancing duct to collect dust in the dust collection hood. Moreover, the negative pressure enhancing chamber has an opening edge mating the shape of the inner side of the wall of the dust collection hood to increase covering range of the airflow.