The possible effects of several environmental conditions on the catches of anchovy with a set net located in the water off Samchunpo were observed during the period of June 1∼Sep. 30, 1975. The best catches of anchovy were made when the surface water temperature was 24∼25$^{circ}C$. If the surface temperature were below 18$^{circ}C$ or above 26$^{circ}C$, the catches were significantly smaller. The best catches were observed when the salinity was 28∼30 . If the salinities were below 25 or above 33 , the catches were considerably smaller. Increases in the catches were noticed as the transparency of the water decreased for certain range, and the best catches were made when the transparency was 2.0∼2.4m. The catches of anchovy were appeared to be related to the passage of cyclones, and significantly increased catches were observed 2 days after the passage of a cyclone. Significantly increased catches were also made when the atmospheric pressure was higher than 1,015mb under the influence of a tropical maritime air mass. the catches were found to be related to the tidal differences, and the average catch per day during the spring tide was 47 times as much as that of the neap tide.