Emulsifing ability of Polyoxyethylenemodified-polydimethylsiloxane (POES) in Silicone-Water system was investigated. 9 kinds of POES were synthesized by addition reaction of SiH and CH2=CH-in the presence of Platinum catalyst. These were devided into 3 type by molecule structure, Polyoxyethylene (A)-Polydimethylsiloxane (B) linear block copolymer, A-B-A linear block copolymer and bran ched copolymer with side chain of A. Emulsifing ability of these POES was evaluated by ob serving the physical appearance of the mixture of each Silicone and Water with 4% of POES. Some of A-B and A-B-A linear copolymer showed higher emulsifing ability than branched copolymer. These copolymers are considered as promising emulsifier for silicone.