Encapsulation in glassy carbohydrates via extrusion is the low temperature technology and considered to be suitable for encapsulating heat-sensitive materials. The selection of matrix is the important factor. The temperatures of extruder barrel were T₁ (65 ℃)，T₂ (85 ℃)，T₃ (105 ℃) and T₄ (95 ℃). Screw speed was 60 r/min and the feeding speed was 1.2 kg/h. The effects of matrix including maltodextrin, maltodextrin added sucrose and maltodextrin added modified starch on the extrudates was investigated. The results showed that the extruded products were the glassy state. The glass transition temperature (T_g) of the extrudate used maltodextrin as only matrix were 48.52 ℃. Adding sucrose to maltodextrin made T_g of extrudate decrease. While adding modified starch to maltodextin made T_g of extrudate increase. With the temperature increasing, the glassy state was destroyed and orange oil released gradually from thermogravimetric analysis. The release rate of orange oil was slower from composite matrix than single matrix. The results of scanning electron micrographs showed that orange oil was dispersed with small oil drops in glassy carbobydrates.