The melt flow properties of LDPE/HDPE blends in capillary extrusion have been investigated It is found that the End pressure losses (Delta P-end) increase as a form of non-linear function with increasing the wall shear stress (tau(w)) and the Delta P-end value of the sample is the minimum at the weight percentage content of HDPE (Phi(HD)) being 50% when the tau(w) is fixed. The blend melt flow basically obeys the power law and the sensitivity of the melt viscosity (eta(w)) on the wall shear rate (gamma(w)) is weakened with increasing the phi(HD) Synergistic effect is obvious for the blend melts under experimental conditions. When the tau(w) is 42.5 KPa, the eta(w) value achieves the maximum at the phi(HD) = 20%. In addition, the relationship between the eta(w) and the test temperature approximately accords with the Arrhenius equation as the tau(w) is fixed.