β-1,3-glucanase (EC 3.2.1.39), a potential pathogenesis-related protein, was induced 3-fold in leaves after treatment o 40-day-old soybean plants with 10㎚/㎖ ethylene for 30 hr. The enzyme was extracted in 50 mM sodium citrate (pH 5.0), and then purified by heat treatment, (HN₄)₂SO₄ precipitatiio, DEAE-Sephadex A-50, CM-cellulose and Sephadex G-75 chromatography. β-1,3-glucanase was enriched 8.3-fold with a yield of 8.4%. The purified enzyme gave a single band on SDS-PAGE, and its apparent molecular weight was 33 KD. The enzyme showed optimum pH 5.0 and broad pH stability, and showed optimum temperature of 50℃ and thermal stability below 60℃. Km and Vmax of the enzyme were 50 ㎎/㎖ and 67 nmole Glu/min, respectively, for larminarin as a sustrate. β-1,3-glucanase was significantly inhibited by 10 mM Cu^(++), Hg^(++), or Ph^(++). Supported by PMBBRC, Korea Science and Engineering Foundation, Korea.