Abstract: The study investigates the tissue expression of transferrin (Tf), tumor necrosis factor alpha (TNFα) and C-type lysozyme (C-Lys) in healthy Trachinotus ovatus after it was infected with Photobacterium damselae subsp. piscicida in kidney. The results show that after infection, the accumulative mortalities of T.ovatus reached the maximum in 48 h (76.4%); and the colony of P.damselae in T.ovatus′ kidney continued to decline in 3~96 h from 1.07×10⁶ CFU·g^-1to 1.29×10³ CFU·g^-1. The Tf and TNFα expressions were the highest in the liver, and the C-Lys expression was the highest in the head kidney in healthy T.ovatus. After TOS1 infected, the Tf expression in 3~12 h in test group was higher than that of control and was the highest in 6 h (17.99 times as high as that of control). The TNFα expression of the test group was higher than that of the control after infection of 3 h, 6 h and 24 h. The TNFα expression was the highest in 24 h (6.05 times higher than that of control). The C-Lys expression in infection group was lower than that in control in 3~96 h. The study indicates that the Tf and TNFα expressions can be promoted while C-Lys will be suppressed after TOS1 infection in T.ovatus′ kidney.