In bioreactor, it often monitors some procedure parameters such as temperature, pH , and dissolved oxygen values to monitor fermentation process, but these parameters may be instability and delayed. Calorimetry hasn’t distinctiveness, virulence and doesn’t be sensitive to electrochemistry. So it can be used in some kind of culture fluid, even so it can be used in muddy fluid that photometers can’t be used in. Relative to other monitoring ways, calorimetry’s response time is short, so calorimetry is well suited to monitor bioprocesses on line. Calorimetry only needs normal standardize monitoring units, and this normal standardize monitoring units is be widely used in industry. Calorimetry as a simple alternative is beginning to be used in monitor bio-fermentation process.