Undoped and palladium doped titania nanoparticles have been prepared by sol–gel method using isopropyl alcohol as solvent. The products have been characterized through XRD, FESEM, TEM, HRTEM, FTIR, specific surface area analysis and ICPOES technologies. The antibacterial activities of the products against Escherichia coli (E. Coli) have been investigated by microcalorimetric method and antibacterial circle method, respectively. The process of E. Coli growth and metabolism affected by nanoparticles has been monitored using a Thermal Activity Monitor (TAM) Air Isothermal Calorimeter by microcalorimetric method. The results indicate that undoped and palladium doped titania nanoparticles present better antibacterial activities. Among them, 3 mol% Pd doped titania nanoparticles exhibit the best antibacterial activity due to the lowest value of minimum inhibitory concentration (MIC). This result is in accordance with that of the antibacterial circle method. This work provides a general analytic technology to quantification study antibacterial activity of nanomaterials against various bacteria by microcalorimetric method, which could be a potential application in the future.