Xinjiang Arnebia euchroma is a traditional Chinese medicine, which belongs to the national second-class protected plant. This species has a typical type II style phenomenon. In this paper, the morphological characteristics, population structure, reproductive system, pollination ecology and fruiting mode of Arnebia euchroma in Xinjiang were studied comprehensively by combining field observation with indoor observation. The main results are as follows: (1) Arnebia euchroma is a perennial herb with abnormal style, and its population consists of two plants with long style (Pin) and short style (Thrum), and the frequency of the two plants in the population is close to1:1; Phenology is obviously affected by altitude. The germination, initial flowering, full flowering and final flowering of low-altitude groups are earlier than those of high-altitude groups, and the flowering duration is longer, while the fruit ripening and yellowing period is later than that of high-altitude groups. (2) The typical characteristics of plants with different styles: the stigma and stamens of long style flowers and short style flowers have interactive correspondence in vertical height, and there is no overlap in spatial position; The anther of short style is larger than that of long style, but the stigma is obviously shorter than that of long style, and there is a significant difference between them. The pollen of the two flower patterns is dumbbell-shaped, the polar surface is round and the middle is constricted. The pollen quantity of single flower of long style flower is larger than that of short style flower such as banquet flower, but the pollen quantity is obviously smaller than that of short style flower. (3) The flowering phenology of the two flower types is consistent. The flowering period of the population can last for about 30 days; Most flowers open at 8: 00- 12: 00 in the morning. When they bloom, the anthers crack, and the corolla color gradually changes from deep purple to pink. The single flowering period is about 6-7 days, and the stigma of the whole single flowering period is acceptable. (4) The pollen amount of single flower of long style flower and short style flower is 624 000195 640 and 270 300 93 570, respectively, and the difference between them is significant. The larger pollen amount provides a guarantee for cross pollination. The P/O values of long style flowers and short style flowers are 156000 48909 and 67583 23392 respectively, which should belong to a specific outcrossing breeding system. The hybridization index OCI(≥4) and pollination experiments also show that this species has strong self-incompatibility and belongs to the mating mode of obligate outcrossing. Cross-pollination between the same flowers is fertile, but its seed setting rate is obviously lower than that of cross-pollination, which shows that the combination of pollen and stigma between different flowers has stronger affinity and competitiveness than that between the same flowers. (5) It is an insect-borne plant, and many insects pollinate it. The main pollinators are Anthophora (Melea) Plagiata Illiger, Bombus (Underground Bombus) Melanurus Lepeletier and Bombus (Mega Bombus) Sushkini (Skorikov). And Skorikov, a defector from Sibiricobombus. The main pollinators visit flowers at the peak on sunny days 12: 00- 14: 00, reaching 2.9 times/h ... (6) Different populations, different habitats of the same population and different years in the same habitat all show different degrees of differences in seed setting characteristics, mainly in the average seed setting rate of plants, 1, 2, and 2. In the same population, the number of branches, flowers per plant, seed setting rate, seed yield per plant and seed setting rate of long style plants are higher than those of short style plants. These characteristics are related to plant size, time and location of flower and fruit differentiation, pollen source, pollination system, pollen flow and habitat conditions.