Abstract: A new method had been developed for the fast determination of chloramphenicol, florfenicol and thiamphenicol in eggs by ultra performance liquid chromatography-triple quadrupole/linear ion trap combined with library search. The egg extract was concentrated up to dryness after extracted with acetonitrile and then dissolved in water with n-hexa purified. After gradient elution separation on Phenomenex Kinetex F5 LC column (100 mm×3.0 mm, 2.6 μm) using acetonitrile and water as the mobile phases, a multiple reaction monitoring (MRM) scan as survey scan and an enhanced product ion (EPI) scan as dependent scan were performed in an information dependent acquisition (IDA) experiment. Finally, the identification of the drugs were carried out by library search with a newly developed MS/MS library. Chloramphenicol was determined by internal standard method, as florfenicol and methamphenicol by external standard method. The linear ranges of chloramphenicol and florfenicol were good in the range of 0.03~50.0 μg/L, and of thiamphenicol was good in the range of 0.06~50.0 μg/L. The correlation coefficient (R) of them were all over 0.999.The average recoveries of chloramphenicol, florfenicol and thiamphenicol in eggs varied from 90.1% to 120.0%, and the relative standard deviations were between 4.2% and 11.9% at three spiked levels. The limits of detection (LODs) ranged from 0.05 to 0.10 μg/kg. The method is simple, effective, and can be applied to real samples.