The lighting system for plant cultivation (9) according to the present invention is configured to be capable of switching between an intermittent lighting mode and a continuous lighting mode. The intermittent lighting mode is a mode in which a light source emits light with a lighting cycle comprising a light period of turning on the light source for a predetermined time period and a dark period of turning off the light source for a predetermined time period. The continuous lighting mode is a mode in which the light source continuously emits light. In another aspect, the lighting system for plant cultivation (9) comprises a light source (3), a light source driving unit (2) that drives the light source (3), and a control unit (1) that transmits a pulse signal to the light source driving unit (2). The control unit (1) comprises a first pulse generating unit (11) that generates a first pulse signal (S1) of a predetermined frequency, a second pulse generating unit (12) that generates a second pulse signal (S2) of