Abstract: In order to evaluate the emission of CO from tobacco heated at low temperature, a quantitative and real-time analytical method was developed via a test system combining a steady-state combustion pyrolysis device with non-dispersion infrared analyzer(SSTF-NDIR) on the basis of controlled equivalence ratio technique. The effects of temperature and equivalence ratio(φ) on CO emission were studied. The results showed that: 1) SSTF-NDIR test system could real-timely analyze the CO emission from tobacco heated at low temperature. 2) Comparing with combustion at high temperature, the CO emission from tobacco heated at low temperature was remarkably lower at a fixed equivalence ratio; temperature affected the CO emission from tobacco heated at low temperature slightly. 3) When temperature was fixed at 450℃, the CO emission increased rapidly then tended to be steady with increasing oxygen deficiency.