In Tokyo Bay, blue tide is a phenomenon that seawater presents to be milky blue due to reflection of sunshine off surface water in which a large number of sulfur particles suspend. Its occurrence is because of coastal upwelling of the oxygen-depleted water at the bottom of the bay induced by the blowing of a northeasterly wind, consequently leading to many deaths of shellfish and some aquatic animals in the bay. In this study, an analytical solution of minimum wind stress for the occurrence of blue tide on the southeast shore of the bay is presented based on a two-layered model, and comparison with observation data of blue tide from 2003 to 2010 shows the validity of this solution. The results of sensitivity analysis to all of parameters involved in this solution were also found to agree with qualitative understandings of blue tide phenomenon.