A space-saving locking structure without sharp edges for a server cabinet can lock a first housing to a second housing and includes first and second locking members. The first locking member includes a locking portion with a tail portion, the second locking member includes a blocking portion. The blocking portion has a rounded surface such that when the first housing is pressed along a first direction, the first housing approaches and closes with the second housing, the tail portion being set against a top of the blocking portion. When the first housing is further pushed in a second direction, the tail portion slides along the rounded surface of the blocking portion until the tail portion abuts against the blocking portion to lock the first housing to the second housing.