Effects of calibration RFID tags on performance of inertial navigation in indoor environment The hybrid localization system applications nowadays not only mitigate the inaccuracy of standalone RF localization approach, but also increase the reliability in the absence of supporting Radio Frequency (RF) infrastructure. One of the outstanding hybrid approaches is the Radio Frequency Identification(RFID) assisted inertial navigation system, which is notable for its low cost, simple implementation and extraordinary accuracy. Previous work on such hybrid system fails to find out the correlation between the deployment of the multiple calibration points and the indoor localization accuracy. In this paper, we use the Android smart phone to build a hybrid localization platform and conduct measurements with multiple RFID calibration tags. Based on the measurement results, we define a mathematical model which includes the calibration point number, RFID tag density and theRFID tag-to-corner distance to describe the deployment effect on the localization accuracy. Such model facilitates the future study on algorithm design, system evaluation and application development.