A circuit and a method for implementing frequency tripled I/Q signals are proposed, including receiving two input I/Q signals through frequency multipliers so as to generate two frequency multiplied signals and mixing the input I/Q signals and the corresponding frequency multiplied signals through mixers for generating and outputting two I/Q signals with a frequency three times that of the input I/Q signals. The invention eliminates the requirement for high amplitude of the input signals as in the prior art and has lower power consumption and broader bandwidth and can be used as high frequency signal sources in any single chip processes.