A simple, rapid, and sensitive fluorometric method for determining microamount albumin selectively is presented. The fluorescence of 2,5-di(orthoamino phenyl)-1,3,4-oxadiazole is enhanced greatly by the addition of albumin. Based on this, a range of 6.8–47.6 μg/ml albumin can be detected. All other proteins have little interferences on the assay. Experimental parameters are optimized. In detection of serum albumin, the method gives values close to those of the BCG method. Scatchard analyses show that the association constant of bovine serum albumin with oxadiazole is 6.82 × 104M−1. Fluorescence displacement data indicate that oxadiazole binds to the bilirubin site.