Biochemical properties of an enzyme are very important for its applications in various fields. In the present work, we have investigated some parameters affecting to the invertase activity and stability which was partitioned in poly(ethylene glycol)/sodium sulfate aqueous two-phase system (ATPS). The optimum temperature and pH of the invertase were found as 50ºC and pH 5.0, respectively. The enzyme was very stable at the temperature ranged from 25 to 50ºC and also in a pH range of 4.0-7.5. The enzyme was stored at 4ºC and lost about only 47% of its initial activity at the end of two months. Kinetic parameters; K_m and V_max were determined as 4.65 mM and 30 U, respectively. The effect of various effectors on the activity of the invertase was also searched. Especially, Mn⁺² ions showed an activator effect for invertase. Invertases are still efficient tools in various biotechnological applications especially in the food and beverage industry. The results obtained in this study indicate that, characteristic properties of invertase partitioned by PEG/Na₂SO₄ aqueous two-phase system is very suitable for its industrial applications. The relatively wide range of pH and temperature for activity and stability exhibited by invertase could be very interesting for the food processes.