In a Multiple-Input Multiple-Output (MIMO) wireless local area network (WLAN) system, a method is provided for selecting at least one antenna from a plurality of antennas and transmitting a data frame from a station to an access point via the selected antenna or antennas. A method for transmitting data from a plurality of stations to an access point in the MIMO WLAN system includes detecting a channel status of a channel from the access point to each transmitting antenna of the station, selecting at least one transmitting antenna from among the station's transmitting antennas based on the detected channel status, and transmitting a data frame from the station to the access point via the selected transmitting antenna or antennas.