This paper deals with an improved absorption refrigeration cycle with staged absorption. Instead of having only one absorber, the improved cycle uses a series of absorbers among which one is cooled by the external medium and the others are cooled by refrigerant at staged pressures between the evaporation pressure and condensation pressure. Ammonia-lithium nitrates (NH3-LiNO3) are selected as the working fluids and the calculation results for the two-staged cycle and the three-staged cycle are analysed in detail. It is demonstrated that the improved cycle is able to steadily run when driven by low-grade thermal sources as low as 65 degrees C, and to produce deep refrigeration temperature as low as -40 degrees C.