In the autumn of 1962, we carried out a systematic study of the copepods of our seas. The material for study was collected during the years 1951-1963 from the Yellow sea west of 124°E (including Pohai), the East China sea north of 28°N, west of 124°E and the coastal waters of Amoy, Fukien. The copepod fauna of this area had previously been studied by Giesbrecht (1888, 1889), Mori (1932, 1937), Yamada (1933, 1935), Sproston (1949), Chiba (1949- 1950), Brodsky (1957), Cheng (1955), Shen (1955), Shen & Bai (1956), and Enomoto (1962-1963). Mori’s works in 1937 treated more extensively the copepod fauna of our seas than those of the other authors, recording inter alia, 115 species of Calanoida from the off-shore waters of the East China Sea (including Taiwan Strait). The present paper, the first part of our study, treats of the Calanoida. A total of 134 species was identified. Of these, 8 are new and 39 are first records for our waters. Each of the species is described and compared with closely related species. Diagnoses of new species are given below. Type specimens are deposited in the Institute of Oceanology, Academia Sinka.