Almond strains ‘07-3’was used as material and they were sprayed with calcium and calcium ion in-hibitor in flower bud break and expands stage. Branches at full bloom were collected and indoor simulation test oflow temperature carried out. Freezing rate of different processing almond pistil was investigated, by measuring solu-ble sugar content, MDA content, SOD activity and POD activity of pistils of different treatment. The relationship be-tween almond pistil cold hardiness and exogenous calcium was studied. The results showed that exogenous calciumtreatment improved the pistil soluble sugar content, reduced the pistil MDA content, enhanced SOD activity andPOD activity, significantly reduced cold injury of the pistil, improved cold hardiness. Effect of exogenous calciumion inhibitor treatment was on the contrary.