Abstract:Based on the investigation from November, 1994 to October, 1996( except April - July ) in the high sea of tropical Atlantic Ocean ( 09..00..N - 5..00..S, 18..00..W - 34..00..W) by JING FENG NO. 2 longline fishing vessel, 27 species of f ish and one species of sea turtle were ident ified and catch rates of main economic fish were analyzed. Catch rate of Bigeye tuna( Thunnus obesus Lowe) reached the highest( excess over 8 .. ) during February in north latitude and early December in the area 1..S - 5..S, west of 24..W. But in the other area, catch rate fluctuated between 2 .. - 8 .. . Catch rate of yellowfin tuna ( Thunnus albacare ( Bonnaterre) ) reached the highest ( excess over 4 .. ) during November and December ( 1995) in north latitude fishing grounds and early December in the area 1..S - 5..S, west of 24..W. Catch rate of yellowf in tuna in the area 1..S - 5..S, 24..W - 18..W from August to October. 1996 was less than 1 .. . Generally, catch rate of swordf ish was lower than 2 .. in these fishing areas. Other low valued species catch rates were almost less than 1 .. . Effect factors on catch rate were discussed.