Tuna like resources is economically important in the eastern waters. In the past, therewere some studies on tuna like in the costal waters of Taiwan . But in recent years,utilization of the resource is increasing and the landings are oscillating. Assessment of thepresent stock biomass need to be further studied. In the respect of tuna like species, thereare YFT, BET, ALB and BFT in the catch. But in the report of the local fishermen'sassociation, there is no statistic on landings for tunny, i.e. for the landings of tuna likespecies under 10 kilograms. The landings of tunny is increasing in the recent years. Theproject aims to collect biological data, to establish the categorical database of landings bydifferent fishing methods and fishing seasons. Statistical analysis would be conductedusing internal and external hard parts data of the sample fishes. Then establish thedatabase on the characteristics of tuna like fish at juvenile stage. According to thedatabase, the landings of small tuna can be categorized and the proportions of eachspecies can be known to facilitate the stock assessment.