Provided are a Gemini-type alkyl-polyoxyalkylene-modified silicone suitable for use in preparing a silicone emulsion; a production method of thereof; and a defoaming agent composition containing such Gemini-type alkyl-polyoxyalkylene-modified silicone.The Gemini-type alkyl-polyoxyalkylene-modified silicone is expressed by the following general formula (A): wherein each of R1, R2, R3, R4, R5 and R6 represents an alkyl group or the like; n represents an integer of 0 to 300; and (B) represents a group expressed by the following general formula (1) or general formula (2): wherein each of R7 and X represents a hydrocarbon group; R8 represents a hydrogen atom, a hydrocarbon group, a formyl group or an acyl group; and a and b represent numbers satisfying 2≦a≦200 and 0≦b≦200, provided that a+b=2 to 200.