Based on the study of water number, cloud point, surface tension of hyperbranched polyglycerol modified with short oligo(propylene oxide) segments with different structure, the effect of polymer concentration and temperature on the anti-emulsifying behavior of 150SN lubricating base oil is investigated. The results show that HLB (hydrophile-lipophile balance) value, concentration of the polymer significantly affects the anti-emulsifying properties. The HLB value of 14.7~14.9 (water number method) and the cloud point of 58.6°C~65.1°C are favorable for showing better anti-emulsify behavior at the polymer concentration of 2.0×10-2 g/L. Moverover, the anti-emulsifying behavior of these polymers are improved with temperature increasing.