The blood glucose concentrations of volunteers from diabetes patients and healthy adults (all patients and volunteers who joined this experiment gave their consents) were measured by using a modified WQF-200 FTIR spectrometer with a newly designed ATR accessory from the Beijing Rayleigh Analytical Instrument Corp. The determination basis for this technique from the physiological point of view is also discussed based on the experimental results, which indicated that the glucose measured by the FT-Mid-IR-ATR instrument is from the secretions on the skin and glucose components within the body. The secreted glucose components will increase with the time increasing. The authors’ previous study［3-8］ demonstrated 1 120 cm-1 band as an index to characterize the blood glucose. During the experiments, the authors used the band of 1 455 cm-1 as internal standard because of its stability, and because the relative intensity of I1 120/I1 455 band possesses the higher sensitivity. Meanwhile, from the spectra, the relative intensity of I1 120/I1 455 band of the glucose in both sources exhibits a linear relationship with blood glucose concentration within the body. The dried blood has the similar spectra as fingers’. The fingers’ spectra will exhibit higher sensitivity if the time of measurement is longer after washing hand, and the results showed that when measured 10 minutes after washing hand, the sensitivity will be higher than that when measured 4 minutes after washing hand. All the results can be used in promoting a convenient, rapid and noninvasive way to monitor the continuous variation of blood glucose concentration of diabetes patients in real time.