The purpose of this article is to make a brief review on the relationship between thedistribution of zooplankton and fishing grounds of mackerels (Pneumatophros japonicus)and scads (Decapterus maruadsi) based upon the materials collected in 1972--1975.Theses fishes are mainly zcoplankton feeders and also take a little amount of young orsmall fishes. The main coustituents of the food of these fishes are Euphausia pacifica,Calanus sinicus, Laptochela aculeocadata, Parathemisto gavdichaudi etc. It has beenfound that in spring the spawning shoals usually aggregate in the coastal water ofZhejiang Province, where it is rich in zooplankton and the fishes take plenty of foodbefore or after spawning The fishing center coincides usually with abundant zone ofbiomass especially aggregation of Calanus sinicus and Euphausia pacifica. The shoals migrate gradually northeastward and some mackerel schools enter Huang Hai, while thewarm current and the food organisms zone move continuosly along the Zhejiang coast.The feeding grounds of these fishes are situated in the western part of the Kyushu,south western waters of the Chiju Island and near the mouth of Chang Jiang, wherethere is plenty of food organisms. In the late Autumn, with the water temperaturelowering down there is they gradually migrate the wintering ground in the southeastern region of the Dong Hai and it is under the influence by Kuroshio or Taiwancurrent. In this region the food and hydrographic conditions are most favourable tothe aggregation of these schools, so that a fine fishing ground is formed there