The distribution of Beta-1.3-Glucanase in 41 species of marine invertebrates in Vietnam including echinoiderms, bivalves and gastropods was studied. After collection, species names of the invertebrates were identified and samples were kept at 4°C during transferring to the laboratory. The hepatopancreas, crystalline stalks, mesentery or eggs were separated, homogenenised in succinic buffer and concentrated to obtain a crude extract. The crude extracts were applied on a Sephadex G-25 column (1.2 x 20 cm) to remove some small molecules, then enzymological activity was screened with laminaran. The results showed that Beta-1.3-Glucanase were widespread in the animals analyzed. Catalysis conditions of enzyme were also studied in 5 species which had high activity with laminaran, it were Conus quercinus, Haliotis ovina, Perna viridis, Tapes literata and Turbo chrysotomus. These enzymes had different pH optimum and temperature optimum, but almost had high activity in pH range of 4 - 7 and at temperatures of 30 - 40°C. The time for hydrolysis was also various in range from 10 to 30 minutes.