With the help of mechanical mixing method such as Banbury mixer and open 2 roll mill, ethylene propylene diene terpolymer (EPDM) was blended with the chloroprene rubber (CR) then mechanical properties and ozone resistance test of blends were subsequently investigated. It was noted that the hardness increased with an increasing of CR contents. Generally the hardness was increased with heat aging time most likely due to the post cure. In ozone resistance test of blend, after 8 hours a portion of fine crack is obtained for pure CR. It is confirmed that ozone resistance is greatly improved by addition of 25wt% EPDM to CR.