In this paper, we explored to prepare a multi-compositional titanium alloy, Ti-5Al-5V-5Mo-3Cr (Ti-5553), by powder compact extrusion from elemental powder mixtures, and investigate the microstructure variation during the synthesising process and after post heat treatments and the changes of mechanical properties. XRD, OM and SEM were used to analyse the phase constitutions and microstructures of the Ti-5553 alloy at different processing conditions, and tensile tests were conducted to examine their mechanical properties. The results showed that a homogeneous Ti-5553 alloy was successfully produced by powder compact extrusion from the powder mixtures, beta phase was mainly contained in the hot-pressed and 1200 degrees C-extruded Ti-5553 alloy and had an equiaxed microstructure. Different types of alpha phase precipitated from the beta matrix after heat treatment, and this significantly changed the microstructures and improved the mechanical properties of the extruded Ti-5553 alloy, with yield strength of 1250 MPa and ultimate strength of 1300 MPa for the alloy treated at 675 degrees C for 2 h, and the ductility of about 6.1% for the alloy treated at 780 degrees C for 2 h. (C) 2018 Elsevier B.V. All rights reserved.