A fiber optic biodiagnostic sensor system includes a blood vessel insertable pressure distribution measurement device to be inserted in vivo into a blood vessel to measure distributions of temperature and pressure of an object to be measured along a predetermined site, the device having an SM optical fiber deformable by temperature and strain, a structural member being in contact with a portion of the optical fiber to convert pressure of the to-be-measured object to strain of the optical fiber； and an outer layer converting the optical fiber and the structural member. The sensor system further includes a measurement unit emitting laser light into the SM optical fiber, detecting a frequency shift produced in the scattered light, and calculating a blood pressure at a given position of the optical fiber from a pressure change and a strain change of the SM optical fiber that are calculated from the frequency shift.
