Abstract:We examined the virioplankton abundance in the cultured ponds of Aposticchopus japonicus at four areas, namedly Xietun, Fuzhouwan, Xiajiahezi and Dazheng, near the Dalian coast using fluorescence microscopy during the period of March to November in 2007. As a comparison, we also examined the virioplankton abundance in the surrounding seawater of the cultured ponds. It was found that virioplankton abundance varied significantly （P＜0.01）in different areas and periods. Virioplankton on average was between 1.43×109 and 2.54×1010 per liter with the highest in August and lowest in July. Virioplankton was the most abundant in Fuzhouwan area with an average of 1.17×1010 per liter, while it was the least abundant in Xiajiahezi area with an average of 3.89 109 per liter. In single cultured pond, virioplankton showed the higher abundance in the middle area of the pond than the water inlet and water outlet areas. Virioplankton abundance was closely related to the location and the density of the cultured ponds of Aposticchopus japonicus.