Gelatin microsphere (GMS) was prepared through W/O emulsion chemicalcrossline method. The best formula was selected by examining its appearance, size, drug carrier and drug dissolution rate. The experimental results showed that the optimized gelatin microspheres were spherical ball with smooth surface and had well dispersion. The average size of blank gelatin microspheres was 15.84 μm, while the loaded microspheres’average diameter were 33.10 μm. It was also shown that drug loading of microspheres increased with increasing loading capacity, but drug encapsulation efficiency had a trend of climbing up and then decline. The encapsulation efficiency reached the maximum when the dosage ratio was 2:1. And the results show ceftiofur sodium microspheres have sustained release in the PBS buffer of pH7.4.