A total of 702 1‐day‐old male Jiangnan White goslings were used to study the effects of varying levels of Na+ and Cl− on their growth performance and blood parameters. In this experiment, goslings were randomly allotted to nine treatments, with six pens per treatment in a 3 × 3 factorial arrangement, and fed diets with three concentrations of added Na+ (0.10%, 0.15% and 0.20%) and three concentrations of added Cl− (0.15%, 0.20% and 0.25%). The purpose of this experiment was to investigate the sensitivity of goslings to Na+ and Cl− during brooding to determine the appropriate levels of Na+ and Cl− in their feed. The results are as follows: (a) Different levels of Na+ and Cl− in the diet, especially low Na+ and Cl−, significantly affected the body weight (BW), average daily gain (ADG) and feed/gain ratio (F/G) of the 28‐day‐old goslings (p < .05). But Na+ × Cl− has no significant effect on water consumption (p > .05). (b) Serum concentrations of urea increased linearly with Na+ content (p < .05). Serum concentrations of creatinine (CR) and uric acid (UA) increased linearly with Cl− content (p < .05). (c) Na+ × Cl− has a significant impact on the serum sodium (Na) and chlorine (Cl; p < .05). The content of serum Na and Cl increased linearly with increasing levels of Na+ and Cl−. These results show that low levels of Na+ and Cl− had significant adverse effects on the growth of 1‐ to 28‐day‐old goslings. The results of the experiment support a recommendation to supplement the diet of goslings with 0.20% Cl− and not <0.15% Na+.