A lighting string location identifying system for identifying a location of a lighting unit in a lighting string device, the system comprising: a lighting string controller; and a plurality of lighting units, each one of the plurality of lighting units comprising a lighting portion and a controlling chip, wherein the controlling chip comprises an address code identifying the controlling chip, a driving end of the controlling chip is connected with the lighting portion, a controlling end and a power end of the controlling chip is connected to the lighting string controller through a power line, wherein the controlling chip is adapted to acquire controlling command information transmitted by the lighting string controller through the power line, is adapted to compare the controlling command information and the address code and is adapted to determine, based on the comparison, whether to drive the lighting portion or not, characterized in that the system additionally comprises: at least one light sensor configured to detect a lighting variation of the lighting unit; and an identification device, connected with the light sensor and the lighting string controller, wherein the identification device is adapted to divide the address code required for identifying the controlling chip into a plurality segments, and is adapted to transmit the plurality of segments to the lighting units by means of the lighting string controller, the identification device is further adapted to acquire a lighting variation of the lighting unit by means of the light sensor and thereby provide location information of the lighting unit. a lighting string controller; and a plurality of lighting units, each one of the plurality of lighting units comprising a lighting portion and a controlling chip, wherein the controlling chip comprises an address code identifying the controlling chip, a driving end of the controlling chip is connected with the lighting portion, a controlling end and a power end of the controlling chip is connected to the lighting string controller through a power line, wherein the controlling chip is adapted to acquire controlling command information transmitted by the lighting string controller through the power line, is adapted to compare the controlling command information and the address code and is adapted to determine, based on the comparison, whether to drive the lighting portion or not, characterized in that the system additionally comprises: at least one light sensor configured to detect a lighting variation of the lighting unit; and an identification device, connected with the light sensor and the lighting string controller, wherein the identification device is adapted to divide the address code required for identifying the controlling chip into a plurality segments, and is adapted to transmit the plurality of segments to the lighting units by means of the lighting string controller, the identification device is further adapted to acquire a lighting variation of the lighting unit by means of the light sensor and thereby provide location information of the lighting unit. at least one light sensor configured to detect a lighting variation of the lighting unit; and an identification device, connected with the light sensor and the lighting string controller, wherein the identification device is adapted to divide the address code required for identifying the controlling chip into a plurality segments, and is adapted to transmit the plurality of segments to the lighting units by means of the lighting string controller, the identification device is further adapted to acquire a lighting variation of the lighting unit by means of the light sensor and thereby provide location information of the lighting unit.