To thoroughly investigate probing behavior of the tea green leafhopper, Empoasca vitis (G the), on tea plants, determine adequate electrical penetration graph (EPG) parameters as reliable indices for measuring tea plant resistance/susceptibility levels to the leafhopper, and further analyze their potential correlations to the major defensive components in tea leaves, 11 national or regional elite/specificity cultivars, such as Zijuan, Ningbohuangjinya and Huangguangyin, were studied using EPG techniques. Various leafhopper probing behaviors and EPG parameters were analyzed to evaluate the resistance/susceptibility of every cultivar to the leafhopper. Major (primary) tea leaf chemical components were determined using high-pressure liquid chromatography. Our results showed that:1) seven distinct EPG waveforms (Np, A, S, C, E, F, and R) with possible biological significance during leafhopper feeding were recorded, and each waveform and its regular emergence sequence were analyzed. The waveforms E and F, plus the waveform R (with unknown biological significance) were considered to be the resistance-related waveforms. 2) During the 5-h testing period, the numbers of probing instances by the leafhopper on cultivars Huangguanyin and Longjing 43 were the highest, followed by those on cultivars Zijuan, Ningbohuangjinya and Jinguanyin, and the numbers on cultivars Tieguanyin and Anjibaicha were the lowest. The average durations of waveform E on cultivars Tieguanyin and Huangmudan were the longest, followed by the durations on cultivars Wuniuzao and Anjibaicha, and that on cultivar Zijuan was the shortest. The average duration of waveform F on cultivar Huangguanyin was the longest, followed by the durations on cultivars Zijuan, Longjing 43, and Ningbohuangjinya, and that on cultivar Jinguanyin was the shortest. 3) These 11 tested tea cultivars were classified into two groups via cluster analysis based on the number of probing instances, and durations of waveforms E and F as indices; group I:cultivars Anjibaicha, Wuniuzao, Zimudan, Zhongcha 108, Huangmudan, and Tieguanyin and group Ⅱ:cultivars Zijuan, Longjing 43, Ningbohuangjinya, Huangguanyin, and Jinguanyin. The resistance level of tea cultivars in group Ⅱ was stronger than that in group I. 4) From susceptible to resistant cultivars, the total catechin content rose, and it was negatively correlated with the duration of waveform E (P < 0.05); however, the contents of caffeine, amino acids and soluble sugars were not significantly correlated with the duration of waveform E or F. It is suggested that the number of probing instances, and durations of waveforms E and F are relatively reliable EPG indices for measuring tea plant resistance/susceptibility levels to the leafhopper. Waveform R might be correlated with feeding-resistance in phloem, but needs further investigation. Catechins seemed to be the key defensive compounds in tea leaves against the leafhopper feeding. This study provides in-depth reference information for further investigations on the resistance mechanisms of tea plants against pests.