To provide a data transmitting system and a data transmission observing method for data transmission in a computerized tomography apparatus which simplifies error identification and error analysis.

In this data transmitting system in the computerized tomography apparatus or the X-ray apparatus which can perform tomography, a data detecting unit 1 which converts measurement data into a bit stream when the measurement data is detected, and transmits the bit stream to a transmitting device 2 located at the rotating section 4 of the computerized tomography device is provided. The bit stream is transmitted from the transmitting device 2 to a fixed section 5 of the computerized tomography apparatus. At the fixed section 5, a receiving device 3 which receives the bit stream from the transmitting device 2 and transmits the bit stream to an image reconstructing unit 7 is provided. The image reconstructing unit 7 continuously processes the bit stream which is transmitted from the receiving device 3 for an image reconstruction. At least the transmitting device 2 and the receiving device 3 respectively include an error identification module 8 which inspects errors on the bit stream and transmits the identified errors to error processors 9a and 9b. The error processors acquire the quantity, error rates and/or error continuing periods of time of the identified errors, and store them in a log file 10 for an evaluation. Thus, the errors can be identified on real time.