Abstract: Covalent organic framework material (COF-LZUI) was synthesized by the solvent thermal method and Pt-metal was deposited on it by electrochemical reduction of Pt(Ⅳ) to give Pt/COF-LZUI, which was used as immobilization matrix for CRP. Nanoparticles of MnO₂, composite nanoparticles of Pd NPs/MnO₂ and Pd NPs/MnO₂ marked CRP were prepared separately as described in literatures. The above mentioned materials were used to modify GCE giving the sandwich immunosensor for CRP as specified in the procedure of preparation. The structure and crystallization of COF-LZUI were characterized by MAS NMR and XRD, and the morphology of COF-LZUl, Pt/COF-LZUl, Pd NPs/MnO₂ nano-composites were characterized by TEM. Its electrochemical behavior and response to H₂O₂ were studied by cyclic voltammetry and chronoamperometry (i-t). Linearity range of the sensor found was 1-150 μg·L^-1 and value of detection limit (3σ) was 0.33 μg·L^-1.