Journal citation analysis is an objective technique to evaluate periodicals. 17 core journals in oceanography have been analyzed using data. such as times cited, impact factor, immediacy index. source items, references per paper, cited half-life, self-citation, and ranks. listed in Journal Citation Reports, the companion volumes to Science Citation Inder. It was found that Limnology & Oceanography is the most cites journal, with 6,969 citations in 1988. Problems of citation measures are reviewed.