Abstract: Triton X-100/n-hexylalcohol/cyclohexane/water inverse microemulsion, 3 inverse microemulsions containing glycin(Gly), arginine(Arg) or histidine(His) were selected as the template to induce the formation of calcium bilirubinate(CaBR) nanoparticles and the effects of amino acids were investigated. CaBRs were characterized by transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FTIR), ultraviolet-visible spectroscopy(UV-Vis) and zeta potential, respectively. The results show that the global CaBR nano-particles with an average diameter of 80 nm were successfully synthesized in the inverse microemulsion systems, and the stability of suspended CaBR nanoparticles in aqueous solution decreases first and then increases with the increase of solution pH values, and zeta potential absolute value of CaBR particles was 0 mV when the pH of the suspension solution was around 4.9. The addition of each of three hydrophilic amino acids(AAs) is helpful to the nucleation of CaBR and influences the microstructure, morphology and agglomeration of CaBR. Global CaBR nanoparticles also formed successfully in the microemlulsion and the stability of the aqueous suspended nanoparticles increased with the addition of His or Gly, but the average diameters of them reduced to 60 nm or 40 nm, respectively. Irregular CaBR nanoparticles with the smallest diameter were produced in inverse microemulsion containing Arg and were easy to agglomerate in aqueous suspended solution.