The quality of Indonesiam coffee andcocoa products has been declined due to the contamination of fungi producing ochratoxin, a serious human mycotoxin. Therefore, develop-ment of fast, accurate and simple method for early detection of ochratoxin contamination is required. As a part of research attempted to develop early detection technique of ochratoxin in severall commodities, especially agricultural products, the objective of this study was to produce immunochemical reagent for ochratoxin detectionusing immunoglobulin Y (IgY) based on immunochromatographic method. Results showed that OTA-OVA could be synthesized using active ester method with addition of N-hydroxy-succiimide and dicyclocarboimide. The inter-mediate compound produced showed C=O stretching vibrational band at 1600 cm-1 and C-O stretching vibrational band at 1300-1000 cm-1. Antibody-gold nanoparticle conjugate was optimally produced at pH 9 and with antibody dilution of 1:7.5 (v/v). There was 50 nm absorb-tion shift in visible absorbtion after the antibody was conjugated with gold nanoparticle. Even though the test strip did not show clear visual-ization, the cut off of ochratoxin concentrationis obviously determined at 10 ppb. This results suggest thatthe technique could be used to detect ochratoxin contamination.