An LED light set includes a controller connected with an electric plug and a main light string of a plurality of main light bulbs in serial arrangement. Each of the main light bulbs is connected with an associate light string of a plurality of associate light bulbs. A main control IC is provided in the controller to control voltage and current supplied to the main light bulbs of the main light string. An associate control IC is provided within each of the main light bulbs to control voltage and current supplied to the associate light bulbs of the associate light string. The voltage and current supplied to the associate light strings are controlled to be lower than those supplied to the main light string so that conducting wires of each of the associate light string can be made thinner than conducting wires of the main light string.