Abstract: The stability of N-LTNR (normal lead styphnate) and Pb(N<sub<3</sub<)<sub<2</sub< (lead azide) was studied under severe temperature (-70~+130℃) in this paper. For single N-LTNR, the changes of N-LTNR in the DSC (differential scanning calorimetry) furnace under continuous heating and cooling process were observed using camera. It shows that: when the temperature exceeded 110℃, N-LTNR lost its crystal water which led the energetic material to be darker in color, smaller in dimension and lager in volume; when the temperature was below -40℃, the phenomena of crystal breaking and jumping cracking happened. As for the combination of N-LTNR and Pb(N<sub<3</sub<)<sub<2</sub<, the loss of N-LTNR's crystal water may cause the hydrolysis reaction of Pb(N<sub<3</sub<)<sub<2</sub<, so the purity analysis of Pb(N<sub<3</sub<)<sub<2</sub< was measured after the temperature cycling. The results show that purity decreases from 98.6% to 95.26%. Therefore, the using temperature of N-LTNR and Pb(N<sub<3</sub<)<sub<2</sub< should be limited to 110℃.