Abstract: Cu-Cr alloys with different contents were fabricated by vacuum suction casting method. The effects of true contents of Cr in solid solution on lattice parameter and Vickers hardness of Cu-Cr alloys were studied. Results show that the relationships between the lattice parameter and the content of Cr in solid solution, between the microhardness and the Cr content and between the lattice parameter and the microhardness were all linear, when the Cr content in solid solution was lower than its solid solubility. When the Cr content in solid solution was higher than its solid solubility, the lattice parameter and microhardness of the alloy did not varied obviously with the increase of Cr content.