Synthetics of mesoporous carbon (MC) from biomass including sucrose was used as the carbon resource, and eutectic salt (KCl/NaCl) as the porogen agent for the preparation of S-MC (sucrose mesopores carbons). The resultant samples were examined by means of different techniques, including thermal analysis (TGA), FTIR, transmitted electron microscopy (TEM), X-ray diffraction (XRD) and BET measurements. Investigate the efficiency of adsorption of diclofenac by highly mesopores carbons using Ultraviolet–Visible spectroscopy. The final concentrations of diclofenac were measured using Ultraviolet–Visible spectroscopy at different conditions (pH, contact time, temperature, weight of adsorbate, weight of adsorbent).