Lower case of battery module having cooling block and manufacturing method thereof

A lower case of a battery module and a method for manufacturing the lower case that can reduce costs by manufacturing a cooling block using a press method, and can further strengthen safety problem due to a leakage of cooling water. There is provided a lower case of a battery module including a lower case in which a battery is mounted, a lower panel assembled to the lower case, a cooling block attached to the lower panel and configured to form a cooling passage between the lower panel and the cooling block, and nipples mounted in the lower case to introduce and withdraw cooling water into and from the cooling passage, and a manufacturing method thereof.