A battery pack, comprising: a pack case forming an appearance of the battery pack; at least one battery module provided in the pack case and having at least one battery cell therein; and a coolant circulating unit connected to the at least one battery module to circulate a coolant into the at least one battery module, at least a portion of the coolant circulating unit pressing the at least one battery module in the pack case, wherein the pack case includes: a case body configured to accommodate the at least one battery module and the at least a portion of the coolant circulating unit; and a module pressing plate mounted to the case body and disposed opposite to at least a portion of the coolant circulating unit with the at least one battery module being interposed therebetween to press the at least one battery module, and wherein the coolant circulating unit includes: a circulating unit body configured to store the coolant and having a circulation pump for circulating the coolant; and a circulation pipe configured to connect the circulating unit body and the at least one battery module to circulate the coolant into the at least one battery module, the circulation pipe being disposed in the case body to press the at least one battery module. a pack case forming an appearance of the battery pack; at least one battery module provided in the pack case and having at least one battery cell therein; and a coolant circulating unit connected to the at least one battery module to circulate a coolant into the at least one battery module, at least a portion of the coolant circulating unit pressing the at least one battery module in the pack case, wherein the pack case includes: a case body configured to accommodate the at least one battery module and the at least a portion of the coolant circulating unit; and a module pressing plate mounted to the case body and disposed opposite to at least a portion of the coolant circulating unit with the at least one battery module being interposed therebetween to press the at least one battery module, and a case body configured to accommodate the at least one battery module and the at least a portion of the coolant circulating unit; and a module pressing plate mounted to the case body and disposed opposite to at least a portion of the coolant circulating unit with the at least one battery module being interposed therebetween to press the at least one battery module, and wherein the coolant circulating unit includes: a circulating unit body configured to store the coolant and having a circulation pump for circulating the coolant; and a circulation pipe configured to connect the circulating unit body and the at least one battery module to circulate the coolant into the at least one battery module, the circulation pipe being disposed in the case body to press the at least one battery module. a circulating unit body configured to store the coolant and having a circulation pump for circulating the coolant; and a circulation pipe configured to connect the circulating unit body and the at least one battery module to circulate the coolant into the at least one battery module, the circulation pipe being disposed in the case body to press the at least one battery module.