The effects of annealing and aging processes on transformation behavior of the low-temperature superelasticity alloy Ti-50.8Ni-0.3Cr (atomic fraction, %) were investigated with differential scanning calorimetry. The A→R/R→A (A-parent phase, R-R phase) type reversible transformation occurred in the 350-450 ℃ annealed alloy upon cooling/heating, the A→R→M/M→R→A (M-martensite) type occurred in the 500 ℃ annealed alloy, the A→R→M/M→A type occurred in 550-600 ℃ annealed alloy, and no transformation occurred in the above 650 ℃ annealed alloy. The effect of the annealing time on transformation behavior of the alloy is not serious. With increasing aging time t_ag, the transformation type of 300 ℃ aged alloy still is A→R/R→A, the one of 400 ℃ aged alloy changes from A→R/R→A to A→R→M/M→R→A, and the one of 500 ℃ aged alloy changes from A→R→M / M→R→A to A→R→M/M→A. With increasing annealing temperature, the R transformation temperature (δ_R) of the alloy increases first and then decreases, the M transformation temperature (δ_M) increases, and the M temperature hysteresise (Δδ_M) decreases. After aging at 300-500 ℃, the δ_R⁴⁰⁰>δ_R³⁰⁰>δ_R⁵⁰⁰. With increasing t_ag, the δ_R and δ_M increase fast first and then tend to stable, and the Δδ_M decreases fast first and then tends to stable. The R temperature hysteresises in both the annealed and aged alloys are about 4 ℃.