The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for transmitting system information in which a base station that supports a legacy system and an improved-functions legacy system having one or more functions added thereto, transmits system information, wherein said system information transmitting method comprises a step of transmitting a broadcast channel, containing system information for supporting user equipment for the legacy system, in a predetermined number of symbols which follow the synchronous channel in a first subframe of a wireless frame containing a plurality of subframes; and a step of transmitting additional system information for supporting user equipment for the improved system in a second subframe, excluding the first subframe, from among the plurality of subframes. The present invention also relates to a base station which implements said method for transmitting system information.