This invention relates to a test kit for diagnosing hepatic and biliary diseases. The test kit has such advantages as high stability, high accuracy and high sensitivity. The test kit comprises two reagents. Reagent 1 comprises oxidized thio coenzyme, buffer solution, preservative, and anti-interference agent. Reagent 2 comprises 3alpha-HSD, reduced coenzyme, buffer solution, preservative, complexing agent, polymer accelerator, stabilizer, and one of formate dehydrogenase-formic acid-NAD, glutamate dehydrogenase-glutamic acid-oxidized nicotinamide coenzyme, glucose-6-phosphate dehydrogenase-glucose-oxidized nicotinamide coenzyme, glucose dehydrogenase-xylose-oxidized nicotinamide coenzyme, lactate dehydrogenase-alpha-ketoglutarate-oxidized nicotinamide coenzyme, and glycerol dehydrogenase-ethylene glycol-oxidized nicotinamide coenzyme.