Microbulbifer strain CMC-5 was isolated from decomposing seaweeds, and was found to degrade agar, alginate, carboxymethyl cellulose, carrageenan, xylan, and chitin. The extracellular agarase enzyme from strain CMC-5 was purified 103-fold by ultrafiltration, ion-exchange chromatography, using diethylaminoethyl sepharose FF, and gel filtration, using sephacryl S-300HR, with a yield of 6.7%. Zymogram and protein staining of the purified agarase on a SDS-polyacrylamide gel revealed a single band, with an apparent molecular weight of 59 kDa. The purified enzyme was endo-type ${eta}$-agarase, as it was able to hydrolyze the ${eta}$-1, 4 glycosidic linkages of agarose, releasing neoagarotetraose and neoagarohexaose as the end products. The optimum pH and temperature of agarase were 7 and $50^{circ}C$, respectively. Thermal stability studies indicated that the agarase retained 62% of its activity after incubating at $50^{circ}C$ for 30 min. Treatment with EDTA reduced the agarase activity by 54%. The agarase activity was stimulated by the presence of $Ca^{2+}$ and $Mg^{2+}$ ions; whereas, $Zn^{2+}$, $Hg^{2+}$, $Cu^{2+}$, $Fe^{2+}$, and $Co^{2+}$ abolished the activity. Further, the presence of NaCl at concentrations lower than 100 mM caused a decrease in the agarase activity; whereas, the activity was enhanced up to a concentration of 500 mM.