8 independent SPQC sensors is parallel connected to form a muti-channels detecting unit.Electrodes are immersed into culture medium to detect conductivity change of solution.The cell constant k is determined as 0.05m

and the sensitivity interval of the device is from 550 to 600μs.To maintain sensitivity of SPQC sensor

a novel culture medium（a mino acid broth） AaB is developed.FDT is obtained veraciously by using fitting-differentiating method.Common pathogens S.aureus and S.dysenteriae are determined with the automated detecting device and methods mentioned above.Results show that the calibration curves of FDT against density of bacteria show a linear correlation coefficient（R>0.99） over

the range of 10

1

06 CFU·mL-1.Detection results are all inside the 95% confidence interval of standard pour plate counting method.The reproducibility is also reviewed

and the device is still stable and sensitive.