1433 protein is an important signal transduction regulator in plants and plays significant roles in carbon metabolism, stress response, growth and development, etc. In order to indepth analysis the biological function of 1433 protein family in cassava, we constructed the prokaryotic expression vector pET30aMeGRF3 of MeGRF3, a member of cassava 1433 protein family, via enzymes digestion and ligation, and then transformed it into Escherichia coli Rosetta (DE3) strain by heat shock method to induce the expression of MeGRF3 fusion protein. The purified MeGRF3 fusion protein was used to immunize the New Zealand male rabbits to prepare the polyclonal antibody, and then the titer and specificity of polyclonal antibody were detected. The results showed that: (1) the prokaryotic expression vector pET30aMeGRF3 of cassava MeGRF3 was successfully constructed, and the fusion protein with MeGRF3 and six His tags was induced and expressed. (2) The MeGRF3 fusion protein was mainly in the form of inclusion body, and its molecular weight was about 33 kDa. (3) The antibody titer determined by indirect enzymelinked immunosorbent assay (ELISA) was 1 024 000. (4) The bands with the same molecular weight of MeGRF3 were detected in leaves, stems, barks and roots of cassava via Western blot, indicating that MeGRF3 was expressed in all of the four tissues, but mainly accumulated in the stems and roots. The results showed that the MeGRF3 polyclonal antibody successfully prepared in this study had good specificity.