The purpose of this study is to rear yellow fin tuna(Thunnus albacares) breeder candidates and develop techniques of tuna breeding and larval culture. At present, a batch of 3-5 years old tuna are raise well in a round concrete recirculating tank system. Throughout all this study, pond water is good in transparency and quality parameters were still steady except phosphate. Therefore, we will try to keep water quality invariable by cultivating the macroalgae (Ulva lactuca) with the recirculated seawater for absorption of nitrogen and phosphate . We also feed tuna with hormones (LHRH-a, HCG…, etc) and improve bait kind and quality for stimulating natural spawning of yellow fin tuna in recirculating pond systems. Record the activity of tuna and check whether fertilized- floating eggs exist on the surface of water every day.Finally, we expect to set up the techniques of tuna artificial breeding and culture, and can be applied to other pelagic marine fish