Effect of seawater temperature (temperature) on the production of anchovy, Engraulis japonica and laver, Porphyra tenera Kjellman, were investigated in the eastern part of South Sea of Korea (ESS). Bimonthly temperature data (Feb., Apr., Jun., Aug., Oct., Dec.) from 1980 to 2002 were collected from Korean Oceanographic Data Center (KODC) and monthly anchovy catch and laver production from 1980 to 2002 were used from published sources by the Ministry of Maritime Affairs & Fisheries, Korea. Effects of temperature on the two organisms were examined in four cases. In case of lower anchovy catch and higher laver production (1993), temperature during main spawning season of anchovy was about $0.2-0.6^{circ}C$ lower than normal condition, and temperature during seed collecting season of laver in Namhaedo, Kojedo went down below $22.0^{circ}C$. In case of higher anchovy catch and higher laver production (1995), optimum temperature for catch was formed in main fishing ground, temperature for seed collection was lower than $22.0^{circ}C$, In case of lower anchovy catch and lower laver production (1996), temperature for spawning and catch was about $0.6-1.6^{circ}C$ lower than normal condition, and temperature during seed collection in nursery was about $0.5-1.0^{circ}C$ higher than optimum temperature for seed collection. In case of higher anchovy catch and lower laver production (1998), temperature during main fishing and spawning season was about $1.0-1.8^{circ}C$ higher than normal condition, and temperature during laver seed collection in nursery was $1.5^{circ}C$ higher than optimum temperature for seed collection.