Abstract: Ammonia, a ubiquitous pollutant in the aquatic system, has been proved to be high toxic to fish. The early life state of fish is acturally more sensitive to the influence of external environmental factors than adult fish since its antioxidant and immune systems are in lower level. However, there are limited information on difference responses of different species of fish larvae to ammonia stress. Aim to explore the effects of ammonia on the antioxidant and non-specific immune response of different species of fish larvae, four different feed-habits species of fish larvae (omnivory silver carp Hypophthalmichthys molitrix, herbivorous grass carp Ctenopharyngodon idella, Wuchang bream Megalobrama amblycephala and predacity yellow catfish Pelteobagrus fulvidraco) were selected and exposed to different concentrations of total ammonia nitrogen (0, 1 mg/L, 2 mg/L and 3 mg/L) for 96h. The results showed that acute ammonia exposue caused significant decrease of body length on four species of fish larvae in a dependent-concentration manner (P<0.05). Meantime, ammonia exposure significant decreased levels of total antioxidant capacity (T-AOC), catalase (CAT) and glutathione peroxidase (GPx) in four species of fish larvae (P<0.05). Also, 2 and 3 mg/L ammonia significantly reduced the activities of superoxde dismutase (SOD) in the larves of grass carp, Wuchang bream and yellow catfish (P<0.05). As for antioxidative-related genes, significant decrease of transcriptional levels were only detected in yellow catfish gpx and silver carp sod after ammonia exposure (P<0.05). In terms of immune parmameters, ammonia exposure significantly up-regulated transcriptional levels of immune-related genes in four species of fish larvae except silver carp interleukin1β (il1β) (P<0.05). By contrast, significant decrease of lysozyme contents were observed in grass carp larvae after ammonia exposure, and significant increase of lysozyme contents were detected in yellow catfish larvae exposed to 2 mg/L ammonia (P<0.05). The results of two-way ANOVA also confirmed that ammonia could caused to varying degree changes for all parameters including antioxidant enzymes, immune indexes and immune-related gene expression in four species of fish larvae (P<0.05). There were significant differences on levels of T-AOC, CAT, GPx, C3 and the gene expression levels of cuznsod, gpx, il1β, c3 among four species of fish larvae. However, interactive effects of ammonia and species were only observed on C3 contents and the expression of genes gpx, tnfα, il1β and c3 (P<0.05). In summary, ammonia exposure caused oxidative stress, decreased the antioxidant capacities and disturbed innate immune responses in four species of fish larvae, which led to growth retardation. Among four species of fish larvae, the predacity yellow catfish was the weakest to ammonia tolerance, the herbivorous Wuchang bream and grass carp is the next, and omnivory silver carp were the strongest.