Helopeltis theivora Waterhouse belongs to the genus Helopeltis of the family Miridae of the order Hemiptera, and is one of the most important sap-sucking pests in the tropical tea plantations in Hainan, China. The nymphs and adults of H. theivora mainly damage by piercing and sucking in the young tissues of tea shoots, which causes the black brown spots that necrosis on the leaf and results in the reduction of tea yield and quality. The research on the H. theivora in Hainan tea region is still rare. In this paper, we first investigated the external morphological characteristics of H. theivora, then, the growth and development characteristics such as egg hatching, nymph molting, and adult emergence, as well as the behavioral characteristics including feeding, mating and oviposition were recorded and analyzed, respectively. The results showed that the egg of H. theivora was in a sausage shape, with two respiratory processes on the egg operculum at different length. The color of the freshly laid egg was white. It was then gradually transformed to the orange and ultimately exhibited the orange-red as it approached incubation. The nymphal stage was divided into 5 instars, the color of the freshly hatched nymph was orange-red, and then gradually turned to pale green and green. The adult H. theivora possessed a small head, an elongated beak, and two black compound eyes. The antennae presented filamentous, and the length was twice more than the body. The color of adult H. theivora was brown or yellowish brown. The duration of incubation of H. theivora was (53.25±9.00)min. The hatchability was very low while the rate of egg- hatching was only 69.9% under the laboratory conditions. The moulting of nymphs and the emergence of adults happened mainly on the back of leaves, hanging upside down, and the duration was (6.20±0.97)min and (8.40±1.33)min, respectively. Particularly, as approached to the molting and eclosion, the feeding frequency became significantly less and the activity became weaker. The H. theivora preferred to sucking the saps of the young leaves and stems of tea shoots, and the feeding time was mainly concentrated in the evening. The mating behavior of adults H. theivora mainly happened between 9: 00 and 10: 00 and between 17: 00 and 18: 00, and the duration of each mating was (117.75±18.70) min. In addition, when a female decided to refuse a male’s request for courtship, it generally rolled her abdomen inwards. The stage of the fertilized egg of H. theivora was short. During the oviposition, the female arched itsr abdomen, its head was downward, and the whole body was in a curvedly arched state. The oviposition site was mainly in the epidermis of the tender stems, while a small part of eggs was laid in the petiole and leaf vein. The egg stage was 6-8 days. The results of this study would provide a theoretical basis for the further study on the morphological identification and behavioral ecology of H. theivora in Hainan tea region.