An interference alignment (AI) method for an uplink in a wireless local area network (WLAN) system, an access point (AP) and a user terminal for performing the same, and the AP that may select an interference space, broadcast information on the selected interference space, select a user terminal to be assigned a data transmission opportunity based on leakage of interference (LIF) information received from at least one user terminal, receive data from the user terminal, and decode the data using a minimum square error (MMSE) based receiving filter.