TC18 titanium alloys are widely applicated in high strength structural alloys due to its high strength and perfect toughness. The effects of deformation temperature and heat treatment on microstructure and mechanical properties of TC18 alloy was systematacially studied in this paper. The result shows the basket-weave structure obtained via single phase forging and dual phase heat treatment has the best combination properties including high strength, toughness and good elongation. While the duplex structures obtained via dual phase forging and dual phase heat treatment has relative low strength, poor toughness and the best elongation. For the basket weave structures obtained via single phase heat treatment has the best strength and toughness, while the elongation is poor. The specimen annealed at dual phase region show obvious ductile fracture, while annealed at single phase region shows the mixture fracture mode. The equiaxed α phase can triggered multiple slip system which more than lamellae α phase result in better ductility.