This thesis focuses on the development and characteristics of a resonant sensor based on MEMS, which is used for real-time measurement of blood viscosity. The research mainly concentrates on the non-Newtonian fluid behavior related to immediate medical diagnosis. To understand the rheological properties of human blood, including its shear thinning characteristics, Preparation of blood mimicking fluid,we conducted a comprehensive literature review. Based on these insights, we prepared a  blood blood mimicking fluid using xanthan gum and a water-glycerol mixture to replicate the shear-dependent viscosity observed under physiological conditions. The sensor operates by monitoring the changes in its resonant frequency and quality factor when interacting with the fluid, and captures the mechanical response through impedance analysis and Doppler vibrometry. The rheological behavior is modeled using the power law method, allowing the extraction of viscosity over a range of shear rates. Experimental results demonstrate the sensitivity of the system to changes in fluid viscosity, verifying its potential for low-cost, compact, and rapid diagnosis in portable or clinical settings.