Today, halojenated compounds for flame retardancy are mainly used in the industry. Until very recently, especially polybrominated diphenyl ethers (PBDEs) were on the main materials used to plastic components. Europe banned the use of two formulations, PBDe pentaBDE and octaBDE in 2004. A third compound, decaBDE, was banned 1 April 2008 by the European Court of Justice. The use of decaBDE, the only PBDE still on the market in North America, in mattresses and residential upholstered furniture produced and sold in that state, and extended the ban to electronics in 2010. Due to health and environmental reasons new flame retardant compounds are necessary. There are many inorganic filler for flame retardancy present in the industry. Zinc borate is one of the example for inorganic filler that can be used in polymers (PET, polyamide, polyethylene, rubber etc) and paint formulations. However, Zinc borate can aggregate in the polymer matrix and effect the polymer properties. Meanwhile, groving interest for flame test and retardancy behaviour studies for new additives will be important. In this study, phosphonate ester and phosphonic acid based homo and block copolymers, derivated with ROMP method, synthesized and their flame retardant properties were investigated. Flame retardant properties of the synthesized polymers were also tested by TGA and LOI analysis.