An apparatus for monitoring a laser welding bead irradiates a laser to a surface of a welding bead when welding with a laser welding machine, collects a signal reflected from the surface of the welding bead as an image signal, and then extracts at least one feature variable of a bead shape using the collected image signal. Then, the apparatus for monitoring the laser welding bead determines welding defects using the at least one feature variable, and controls an operation of the laser welding machine according to whether or not the welding defects are generated.