The recent emergence of electronic commerce could provide different opportunities to small firms in overcoming part of their technological, environmental, organizational, and managerial inadequacies. However, recent research provided a gloomy picture about electronic commerce uptake and use in small firms. Until now few small flrms adopted electronic commerce. This phenomenon gives us several implications. One of the implications is a need to generate more research to small firms' uptake and use of electronic commerce. So, this research aims at what is determinants in small firms' adoption of electronic commerce, especially business - to - business(B2B). Several previous studies were identified various influential variables in adoption of small firms' electronic commerce. To some extent, by industries these variables may be different in influencing B2B adoption of small firms. This study selected fishery industry's wholesale firms as survey domain. Then, It selected some variables from previous studios and group them in several factors for consistently comparing variable's influential power. Through hierarchical influencing model of B2B adoption, managers who worked for fishery wholesale firms were surveyed. Among the first level's factors of the model, business factor was identified as the statistically most influential factor in B2B adoption. Technological factor and environmental factor at the frist level were identified as relatively less influential factors. Among the second level's factors of the model, it was statistically significant only that technological usefulness factor was more influential than technological burden factor in B2B adoption. And among the third level's factors of the model, it was identified that formal plan and task team for B2B, top management support, and mutual beliefs of inter - firms were statistically more influential than related variables in B2B adoption. These results give us some implications. First, fishery wholesale firms recognized B2B as a new business paradigm, and technological problems as not obstacles in adopting B2B. Thus it would be possible to activate the fishery B2B if they were guided to getting B2B benefits and B2B's relative advantages. Second, they considered the power of influential factors might be different by B2B stages. That is, top management support was more important in the B2B introduction stage, and formal plan and task team for B2B and mutual beliefs of inter - firms were more important in the B2B operation stage.