Extracts of natural products containing algae, algal lactobacillus ferment lysate and herb applied on the fish and shrimp diseases control were studied. Active substances were screened with in vitro antibacterial activity by the well diffusion method. The oil extracts from three algae species exhibited strong antagonistic activity against Vibrio. The optimum fermentation method for the algal lactobacillus was studied and showed strong propagation and antioxidant abilities. Fifty-five, 30, 29 and 30 prescriptions of herb exhibited antagonistic activity against Photobacterium damselae subsp. piscicida, V. harveyi, V. alginolyticus and V. parahaemolyticus, respectively. By in vivo assessment, algal lactobacillus ferment lysate can increase immune ability of the white shrimp; herb can reduce the mortality of the cobia challenged with P. damselae subsp. piscicida and of the white shrimp challenged with V. harveyi, respectively.