Canine trypsin-like immunoreactivity (cTLI), which is a mirror of the concentration of trypsin and trypsinogen, is a pancreas-specific enzyme and a suitable marker for canine pancreatitis and especially exocrine pancreatic insufficiency (EPI). To develop the immunochromatographic test kit, monoclonal antibodies that recognize cTLI were prepared. Anionic trypsin, cationic trypsin, and chymotrypsin from canine pancreas were successfully purified to homogeneity, using ammonium sulfate fractionation and benzamidine-affinity chromatography. The purification fold for anionic trypsin was 108 times when compared with that of the homogenation of pancreas. The molecular weights by SDS-PAGE analysis were approximately 23 kDa for chymotrypsin and approximately 20 kDa for cationic trypsin and anionic trypsin, respectively. Using the purified trypsin-like proteins, ten hybridomas which secret canine trypsin-specific monoclonal antibody were prepared. Klotz plot indicated that hybridomas, 5G2H10G4 and 2F4A11, have high affinity constant (Ka) of $4.1;{ imes};10^{9}$ and $1.8;{ imes};10^{9}$, respectively. Especially, 5F9H3 showed the cationic typsin-specific binding pattern and its Ka was determined to $4.5;{ imes};10^{9}$. The development of immunochromatographic test kit using these monoclonal antibodies against cTLI will be very useful in the diagnosis of canine EPI or canine pancreatitis.