Abstract: The present invention relates to a post cap for a guardrail equipped with light emission means. The post cap for a guardrail is configured to produce beautiful scenery through variation in the color and the blinking state and to ensure safe nighttime passage through the transmission of signals depending on situations. The post cap for a guardrail equipped with light emission means capable of emitting light of various colors is configured to detect the location of installation and time through the reception of GPS signals and to enable a plurality of post caps to implement variations in color in conjunction with each other through time-based variations in color according to a stored program based on the location of installation.