Chlamydomonas reinhardtii was used as a model organism to deeply study the function mechanism of leucine rich repeat （LRR） in the process of innate immunity in the organism.The physicochemical properties of CrLRR-1 protein including secondary structure， hydrophilicity， and immunogenicity were predicted and analyzed with bioinformatics.The CrLRR-1 specific peptide was artificially designed and synthesized， then coupled with keyhole limpet hemocyanin （KLH） to immunize New Zealand white rabbits.The results showed that the antiserum titer was determined to be 1∶512 000 by indirect ELISA.The CrLRR-1 protein polyclonal antibodies were obtained after sequentially purifying the antiserum with Protein A and antigen affinity.The antibodies prepared with immunoblotting and immunofluorescence detection specifically recognized the endogenous LRR-1 protein in Chlamydomonas reinhardtii， and the CrLRR-1 protein was mainly localized on the cell membrane.It is indicated that the polyclonal antibody against CrLRR-1 protein were successfully prepared and identified.