Disclosed are a method for improving measurement performance of a terminal in a wireless communication system, and an apparatus therefor. Specifically, in a method wherein a terminal performs measurement in a wireless communication system, a method performed by the terminal comprises the steps of: receiving, from a serving base station, configuration information for measurement of a reference signal receive power (RSRP) and/or a reference signal received quality (RSRQ), wherein the configuration information includes port configuration information related to an antenna port to which a reference signal is transmitted and measurement configuration information related to a correlation between a cell-specific reference signal (CRS) and a re-synchronization signal (RSS) for the measurement; receiving the CRS and/or the RSS from a neighbor base station; calculating the RSRP and/or the RSRQ according to the configuration information by using the CRS and the RSS; and reporting the RSRP and/or the RSRQ to the serving base station.