The microstructures and mechanical properties of electron beam weldment Ti1300 alloy after or before different heat treatment were investigated. The results indicated that the various heat treatments before welded treatment cause little effect on microstructures and mechanical properties for different samples. The fusion zone microstructure of non heat treatment (NHT) specimen after welded treatment is mainly composed of columnar β grain and β subgrain with big size, and there is small amount of α phase distributing at high-angle boundary in the fusion zone. This microstructure shows low strength and elongation in comparison to matrix. For the welded specimens after various heat treatments, the morphology and size of columnar β grain or β subgrain, and the distribution of α phase during heat treatment can not be changed. However, the morphology, size and quantity of α phase can be adjusted for different heat treatments, and which determined the mechanical properties of weld joint zone. For the welded samples after annealing or ageing treatment, α phase shows high strengthening effect in comparison to matrix and which result in the failure occurrence in matrix.