In this work we submit a simulation design to sense the water quality using hollow core photonic crystal fiber. The work of this types of optical fibers depending on the variety of structural design and geometrical parameters. The numerical results are studied by using the Finite Element Method (FEM) through COMSOL MULTIPHYSICS simulation software. Different concentrations from (0%) to (100%) of D2O and H2O2 solution in water as sensed liquid had been chosen. The studied HC-PCF investigated for analyzing the relative sensitivity, effective area and confinement loss at wavelength range from (1) µm to (2) µm.