Abstract: The paper deals with the character of immobilized Pseudomonas sp. CTP-01, which was entrapped in gelatin-glutaraldehyde (GGA) and polyacrylamide (PAA), for degrading of parathion. The activity of hydrolyzing parathion for GGA-immobilized cells was 5.8 times higher than that of PAA-immobilized cells. When stored under 4℃, the activity of the GGA-and PAA-immobilized cells could retain 31.3% and 70%, respectively. Optimum temperature for GGA and PAA trapping cell ranged from 50 to 70℃ and 60 to 70℃. The intact cells, however, decreased the activity rapidly when the temperature exceeded 65℃. The experiment of pH adaptation showed that the optimum value was 8.0 for both GGA and PAA immobilization. The activity began to decrease when pit was lower than 7.0 and lost completely at pH 4.0.