Abstract: Biosensors play a vital role in all areas to measure various parameters like temperature, strain, pressure and displacement etc. Measurement of the physical, chemical, and biological parameters in natural environments for ecosystems protection is very important. Fiber optic biosensors have usually been used in medical and biological diagnostics. Fiber optic sensors offer a number of advantages over electric counterparts due to their small size, high sensitivity, and possibility of distributed measurements. Now a day, the technology is heading towards the real time monitoring of parameters and automation in control of process. For that the sensor should be very sensitive and accurate. In the present investigation, a Fiber Bragg Grating (FBG) based, pressure and strain sensor simulation has been carried out using PTOLEMY II software for biological applications. The main advantage is that its sensing principle is based on its reflecting property and it is easy to transmit the measured parameter. Simulation of this sensor will help to understand and predict the value of temperature and strain, based on the shifted wavelength. In the present investigation, a new simulation tool has been developed for Fiber Bragg Grating based temperature and strain sensor, to determine the shift in wavelength. Measurements were made over a temperature range of -20 °C to 140 °C and strain range of 200 to 2000 µε. Temperature vs. shift in wavelength and strain vs. shift in wavelength graphs were plotted. The temperature and strain sensitivity were found to be 5.89 pm/ °C and 0.67 pm/µε. The results are showing very good accuracy and hence the sensor can be effectively used for biological applications with high sensitivity.