A heat-dissipating device is provided. The heat-dissipating device is capable of cooperating a cross-flow type fan, mainly comprising a heat-conductive base plate attached with at least one heat-conductive pipe, and fixedly provided with a plurality of fins on the heat-conductive pipe. An air-outlet gap is naturally formed between any two of the adjacent fins, and an accommodating opening is disposed at an identical location on each of said fins. Within the accommodating opening, a cross-flow type fan is further presented. When fan blades of the cross-flow type fan rotating, an airflow thus generated is allowed for uniformly contacting with each of said fins and discharged through said air-outlet gaps. Thereby, not only the significantly raised effect of heat-dissipation of the heat-conductive base plate, but also the effectively reduced working noise due to a parallel path of the airflow with respect to the fins may be obtained.