This paper investigates the effect of blending on the PE foams morphology and relative bulk density (foam expansion), produced via batch foaming process using CO2 as the blowing agent. Foaming of PE, as a semi-crystalline polymer, is so challenging. The foaming is only possible throw a narrow range of temperature and the gas absorption is limited by the crystalline structure. To yield a foam part with a sound cellular structure, blending found to be highly effective through several mechanisms: decreasing the overall crystallinity, heterogeneous nucleating from the well dispersed secondary phase sites and keeping the main matrix viscosity in a range appropriate for bubble growth. In this study the foaming of LDPE and LDPE/HDPE blends was investigated. The HDPE content varied at two levels (0 and 10% wt.) and two grades of HDPE’s, with different MFI’s, were used. The foaming temperature was also varied in a wide range from 110°C to 140 °C. For the foamed parts, bulk density and cellular structures were investigated as the objective parameters. Results revealed higher cell population density as well as lower bulk density for the foamed parts produced from LDPE/HDPE blend compared with that of pure LDPE. The more uniform cells and high expansion ratio was also noticed for the blends of LDPE with 10% wt. of high MFI HDPE. Results revealed the optimum foaming temperature nearly about the HDPE melting temperature.