Abstract: The aim of the present study was to explore the effects of four kinds of non-nutritive additives on the activity of digestive enzymes, immune function and in vitro digestibility of liver and pancreas of Australian freshwater lobster (Cherax quadricarinatus), and to screen out the appropriate feed additives, so as to provide a theoretical basis for the application and research of non-nutritive additives in feed. Citric acid (S-Ⅰ), complex enzyme preparation (S-Ⅱ), Lactobacillus plantarum plus Bacillus subtilis (S-Ⅲ), and rhizobium plus B.subtilis (S-IV) were used as the non-nutritive additives to feed Australian freshwater lobster for 14 days. Then, activities of enzymes alkaline phosphatase(AKP), acid phosphatase (ACP), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) as well as in vitro digestibility of feed (dry matter digestibility, protein digestibility and amino acid production rate) were detected. S-Ⅰ could significantly increase (P<0.05) the activities of amylase, AKP and SOD in the hepatopancreas of Australian freshwater lobster, and S-Ⅱ could significantly increase (P<0.05) the activities of amylase, trypsin and immune function. The digestive enzyme and immune function of S-Ⅲ and S-Ⅳ were significantly improved (P<0.05). Among the four non-nutritive feed additives, S-IV had the highest dry matter digestibility, protein digestibility and amino acid production rate in vitro. The digestive enzyme activity, immune function and in vitro digestibility of S-Ⅲ and S-Ⅳ were higher than those of S-Ⅰ or S-Ⅱ, and in vitro digestibility of S-Ⅳ was higher than that of S-Ⅲ, so S-Ⅳ was preferred among the four non-nutritive additives.