Abstract: The fabrication and the property investigation of the hybrid nanocomposite material made of poly [2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) polymer and Y3Al5O12:Ce (YAG:Ce) with relative weight ratio of 1:1 in order to apply for optoelectronic and light harvesting devices are reported. Thermal analysis showed that the hybrid materials deterioration/or decomposition when the temperature exceed 200°C under inert gas atmosphere. Rheological measurement concluded that the material solution is able to use for spinning or soft moulding lithography making large or flexible substrate surface. Optical properties of the hybrid material are investigated. The effect of thermal treatment on the optical properties showed that at 180°C under inert gas environment the optical properties were enhanced. A MEH-PPV/YAG:Ce hybrid nanocomposite converted LED lamp was fabricated showing that the hybrid material is suitable as conversion material for white LED fabrication.