This research aims to study the effect of adding Zinc Borate and Aluminum Hydroxide as flame retardants to Low Density polyethylene. Specimens have been prepared through pouring them in a mold. Results have revealed that replacement of certain amount of Aluminum Hydroxide with Zinc Borate could lead to improving the resistance of flame spread in Low Density polyethylene. these improvements were basically due to further contribution of Zinc Borate to the physical barrier mechanism of Aluminum Hydroxide in both gas and solid phases.