The present invention relates to a method for transmitting signals by a user equipment (UE) in a radio resource control (RRC) inactive state or a RRC idle state at a wireless communication system. In particular, the method includes the steps of: measuring neighboring cells; identifying one of the neighboring cells fulfilled with conditions for a cell reselection procedure based on a result of measuring; determining whether to perform the cell reselection procedure with the one of the neighboring cells by considering a timer; and transmitting an uplink data or receiving a downlink data, without performing the cell reselection procedure during the timer is running, when it is determined not to perform the cell reselection procedure.