As a novel drug carrier, protein microsphere has advantages in high efficiency, low toxicity, clear target direction, controllable release, easy degradation etc. In the paper, the Bovine Serum Albumin microspheres carrying 8-phenylamine-1-naphthalenesulfonic acid (ANS) as drug alternatives were synthesized by emulsifying-crosslinking method. Its shape and size were characterized through scanning electron microscope. And the recovery of ANS, encapsulation efficiency of microspheres, ANS loading rate and the cumulative release percentage were measured by ultraviolet spectrophotometer. Smooth surface of microsphere particle with 2-10 μm in size for empty microspheres and 2-14 μm for carrying ANS microspheres were observed under the scanning electron microscopy (SEM). Encapsulation efficiency of microspheres is 88.34%, and the ANS loading rate is 5.49%. ANS release kinetics in vitro was also detected and it was found that the release curve is more in line with Korsemyer-Peppas Model: lnQ=0.115lnt ± 3.857 (R2=0.99067).