AlxCoCrFeNiTi1-x (x = 1.0, 0.8, 0.5 in molar ratio) high entropy alloys (abbreviated as Al-1.0, Al-0.8, Al-0.5 in the paper) were fabricated by repeated arc-melting and casting under vacuum. the effects of Al being replaced partially by Ti on the microstructure, mechanical properties and corrosion resistance in the solutions of 3.5 wt% NaCl, 0.5 mol/L NaOH and 0.5 mol/L H2SO4 were studied. The microstructure analysis showed that the Al-1.0 is mainly composed of single-phase BCC solid solution, while the Al-0.8 and the Al-0.5 consist of BCC and FCC biphasic solid solutions. With the increase of Ti atomic content, the elemental segregation intensifies, the FCC phase increases, and the BCC phase decreases. The results of hardness test and compressive test showed that all of the three alloys have good comprehensive mechanical properties, especially the Al-0.8. In the NaCl and NaOH solutions, the Al-1.0 and the Al-0.5 have similar corrosion resistance, but the Al-1.0 is a better choice out of economic consideration. In the H2SO4 solution, the Al-0.5 has the best corrosion resistance, followed by the A1-1.0 and the Al-0.8. A small amount of Ti addition in AlxCoCrFeNiTi1-x cannot offset the negative effects of the biphasic structure and the intense elemental segregation on the corrosion resistance and the corrosion resistance can be improved obviously Only when the atomic percentage of Ti exceeds that of Al.