PURPOSE: To compare the diagnostic efficacy of domestically synthesized contrast materials (Reyon Iopamidol(R) 300 and Iversion(R) 320) used for IVU, CT, and abdominal angiography in normal rabbits with that of previously used products (Ultravist(R) 300 and Optiray(R) 320). MATERIALS AND METHODS: A total of 60 rabbits were divided into six groups of ten. In the first group, IVU was performed using Reyon Iopamidol(R) 300 and Ultravist(R) 300, while in the second, abdominal angiography involved the use of Iversion(R) 320 and Optiray(R) 320. For three-phase spiral CT, Reyon Iopamidol(R) 300 was used for group 3, Ultravist(R) 300 for group 4, Iversion(R) 320 for group 5, and Optiray(R) 320 for group 6. The degree of contrast enhancement seen on aortography and IVU was evaluated subjectively by two radiologists who reached a consensus while unaware of the names of the contrast materials. On CT, attenuation expressed in Hounsfield Units(HU) was measured using the regions of interest (ROIs) facility in each anatomic region during the early and delayed phases. Adverse events including death occurred during the investigation. RESULTS: There were no significant differences in the degree of contrast enhancement between Reyon Iopamidol(R) 300 and Ultravist(R) 300, as used for IVU, and between Iversion(R) 320 and Optiray(R) 320, as used for angiography. With two exceptions, abdominal CT revealed no significant differences in the degree of contrast enhancement of most anatomic structure. The exceptions were greater enhancement of the portal vein with Ultravist(R) 300 than with Reyon Iopamidol(R) 300 during the delayed phase, and greater enhancement of the aorta with Optiray(R) 320 than with Iversion(R) 320 during the delayed phase. In no rabbit was adverse reaction observed. CONCLUSION: For IVU, angiography and abdominal CT in normal rabbits, Reyon Iopamidol(R) 300 and Iversion(R) 320 provide contrast enhancement comparable to that provided by Ultravist(R) 300 and Optiray(R) 320. In order to evaluate the diagnostic efficacy of these new agents in diseased tissue and in human subjects, further studies are needed.