A liquid-cooling heat dissipation apparatus includes a casing, a first compartment defined in the casing for assembling a liquid driving unit, a cooling plate module on bottom of the casing, a second compartment defined between an inner space of the casing and the cooling plate module and containing a cooling liquid therein. At least one liquid inlet and liquid outlet are defined on the casing and communicated through the second compartment. Therefore, the liquid driving unit and the cooling plate module can be advantageously integrated into the casing while the duct is reduced to achieve compact space. Moreover, the overall structure achieves liquid storing, circulating and heat conveying function.