Surface plasmon resonance (SPR) is a phenomenon which involves the absorption of a p-polarized light by the surface electrons of a metal film (e.g., silver or gold) under specific resonance conditions determined by the dispersion relations of the surface plasmons [1]. This resonance condition is extremely sensitive to the refractive index (RI) and thickness of the dielectric medium (the medium can be a liquid, gas, or solid) in contact with the metal surface. In the last 20 years, SPR has been extensively studied and developed into a useful technique to probe RI and thickness changes which enabled the construction of optical sensors measuring the concentration of chemicals, humidity, pressure, temperature and biomolecular interactions [2-5].     In Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine is experimental investigations of applied aspects for designing SPR biosensors devices “Plasmon” series suitable for operation in labs of biochemical and biophysical profiles. “Plasmon” is a computer-controlled SPR refractometer that implements the Kretschmann prism arrangement for exciting surface plasmons on thin metal film (50 nm) by laser irradiation with wavelength 650 or 850 nm. In devices “Plasmon” series was performed four basic models for difference purposes. For example these devices can provide for investigation human and animal viruses like leukemia and Epstein-Barr virus by one channel refractometer “Plasmon-4” (“Leykoplasm-2”) and 8-channel refractometer “Plasmon-8”, respectively, and providing noninvasive monitoring health state and effectiveness of treatment patient with glioma by 2-channel refractometer “Plasmon-6” [7, 8]. These devices allow measuring the RI over a wide range from 1 to 1.43 with an accuracy ±2×10-5. For measuring high RI (more than 1.43) was developed refractometer “Plasmon-71” with measuring range from 1 to 1.48 (1.5 for low absorption media) with an accuracy ±5×10-6. This device enable to measure, for example, RI and polymerization speed of photopolymer curing adhesives which widely used for connecting optical instrument parts in the producing of precision optical devices and degradation of motor oil [9]. In this year was developed new model 2-channel refractometer “Plasmon-9” with new features for medical and pharmacological investigation.     The main advantages of refractometers “Plasmon” are realization of real time biokinetic, immunosensing and biosensing techniques. In comparison with other SPR devices refractometers “Plasmon” are smaller and chipper, they have flexible construction with easy upgrading possibility.