This study aims to investigate existence of the asymmetric price transmission (APT) in Korean fluid milk market and to estimate the market power of retail participants using the new empirical industrial organization (NEIO) model. In case of the asymmetric price transmission, the analysis is also subdivided into the top three retail channels which have high sales of fluid milk. The results imply that the APT occurred in the stage from farm to wholesale and in the stages from wholesales to retail. In order to investigate an imperfect competition empirically, the degree of oligopsony power is measured. Particularly, with the intention of estimating the oligopsony power of large retailers, it is also tested for discount stores and chain supermarkets separately.