In this study, the extracellular enzyme activity of Bacillus sp. A8-8 was detected on LB agar plates containing 0.5% of the following substrates: carboxymethylcellulose (CMC), xylan, cellulose, and casein, respectively. The ${eta}-1,3-1,4$ glucanase produced from Bacillus sp. A8-8 was purified by ammonium sulfate and hydrophobic chromatography. The molecular size of the protein was estimated by SDS-PAGE as approximately 33 kDa. The optimum pH and temperature for the enzyme activity were 6.0 and $60^{circ}C$, respectiveley. However, enzyme activity was shown over a broad range of pH values and temperatures. The purified ${eta}-1,3-1,4$ glucanase retained over 70% of its original activity after incubation at $80^{circ}C$ for 2h, and showed over 40% of its original activity within the pH range of 9 to 12. This suggests that ${eta}-1,3-1,4$ glucanase from Bacillus sp. A8-8 is thermostable and alkalistable. In addition, ${eta}-1,3-1,4$ glucanase had higher substrate specificity to lichenan than to CMC. Finally, the activity of the endoglucanase was inhibited by $Fe^{3+},;Mg^{2+},;and;Mn^{2+}$ ions. However $Co^{2+};and;Ca^{2+}$ ions were increased its activity.