An analytical method was developed for the determination of carotenoids and their isomers in tomatoes by an improved high performance liquid chromatography（HPLC） method.Hexane-ethanol（3∶4） was chosen as the best solvent system for extracting carotenoids from tomatoes by stirring 30 min using a magnetic stirring apparatus.11 kinds of carotenoids including all trans forms of lycopene，β-carotene，lutein and 8 kinds of cis-isomers were completely separated in 30 min on a Carotenoid C30 column（250 mm×4.6 mm i.d.，5 μm particle） using methyl tert-butyl ether（MTBE） containing 0.05% triethylamine（TEA） as mobile phase A and acetonitrile containing 0.05% TEA as mobile phase B by gradient elution.The flow rate was set at 1.0 mL/min，and the detection wavelength was 475 nm.For lutein，β-carotene and lycopene，the calibration curves were linear in the ranges of 0.1-5.0，0.1-20 and 0.1-100 μg/mL,respectively，with correlation coefficients more than 0.99.The limits of detection（LOD） were 0.13，0.12,0.56 μg/g，respectively，the limits of quantitation（LOQ） were 0.43，0.41,1.88 μg/g，respectively.The intra-day relative standard deviation（RSD） were in the range of 1.2%-5.3%，and the inter-day RSDs were 1.9%-7.5%.The recoveries were in the range of (88.9±6.1)%-(91.7±3.6)%，(92.3±4.3)%-(94.1±6.3)% and （102.6±4.2）%-(107.1±3.4）%，respectively.This HPLC method could be used to separate 11 types of carotenoids in tomatoes completely with a short time and high sensitivity.