A non-targeted metabolomics with automatic chemometric data analysis platform based on ultrahigh performance liquid chromatography－high resolution mass spectrometry（UHPLC－HRMS） was developed for investigation of the differences of chemical components in five tea cultivars．In this study，a total number of forty－five fresh tea samples （one bud and one leaf） from five cultivars，ie．Wuniuzao，Shuchazao，Baihaozao，Pingyangtezao and Shaancha 1 were collected directly from the same tea garden in Xinyang，Henan province of China，which is famous for the main producing area of Xinyang Maojian green tea．The samples were ultrasonically extracted with methanol－water （1∶9，by volume） for 30 min，and centrifuged twice．The supernatant was separated on a Waters Acquity UPLC HSS T3 （2.1 mm × 100 mm，1.8 μm） column by gradient elution，with acetonitrile－water（both with 0.1% formic acid） as mobile phase．The analysis was performed using a UHPLC－Q Exactive－HRMS system with an injection volume of 1 μL．The mass spectra was acquired using an ESI source in the FULL MS/DD－MS,2, （TOP4） under positive ionization mode over the range of mass to charge（,m,/,z,） 120－1 000．The automatic non-targeted data analysis strategy was introduced to screen the metabolites that expressed significantly among different cultivars．The chromatographic and mass spectrographic features of the metabolites could be extracted and registered automatically．Meanwhile，metabolite identification was performed based on high-resolution mass values and mass spectra of screened peaks．The raw UHPLC－HRMS files were analyzed in the automatic data analysis platform and a set of thirty－three metabolites were identified，including one alkaloid，five amino acids，three catechins，four phenolic acids，six nucleotides，and fourteen flavonoids，which primarily enable the varietal discrimination．Finally，hierarchical clustering analysis （HCA），partial least squares－discriminant analysis （PLS－DA） and heatmap analysis were used for discrimination of the samples from various tea cultivars．The results showed that each cultivar has its own characteristics，in which Wuniuzao，Shuchazao and Baihaozao show a certain similarity to each other，but obviously different with the other two cultivars．Furthermore，the metabolites of five tea cultivars are significantly different under the same growth environment and agronomic conditions．Wuniuzao has higher levels of （－）-epigallocatechin and other eight flavonoids including isoquercetin，quercetin-3-O-xyloside and naringenin，etc．Shuchazao has higher levels of catechins and nucleotides．Baihaozao has higher levels of phenolic acids．Shaancha 1 has higher levels of theobromine，phenolic acids and flavonoids．The contents of theanine and arginine in Pingyangtezao were significantly higher than the other four varieties．The results obtained could offer a theoretical guidance for the quality evaluation，breeding and promotion of tea cultivars．