PA 1b (pea albumin 1b), extracted from pea seeds, is thermostable and is multifunctional. It has an attractive peros toxicity, and is also involved in the regulation of callus growth and cell proliferation. Here we report the preparation of monoclonal antibodies (MAbs) against this peptide for further investigation of peptide distribution and functions. PA 1b was coupled to carrier protein using the two-step glutaraldehyde method as an immunal antigen. Five stable cell lines producing anti-PA 1b MAbs were obtained. We analyzed their isotypes, titer, and affinity and found that those MAbs belong to the G(1) and G(2b) subclasses with kappa light chain, respectively. Using these antibodies, a competitive inhibition ELISA was developed, and approximately 15 nmol/L of antigen was detected.