【Objective】 The study was conducted to explore the characteristics of thrips foraging Stellera chamae-jasme and its effect on female fitness of the species in the alpine grasslands.【Method】 Thrips flower‐visiting behavioron Stellera chamaejasme were observed and the flower traits of Stellera chamaejasme were measured.【Results】 Theresults showed that adult thrips tended to forage the inflorescence that were at half ‐ flowering and fully ‐ flowering.The occurrence of thrips in the flowers was much higher at night than during the day. The number of larvae was positivelycorrelated with the corolla entrance diameter,but no significant correlation with other floral traits. Through pathanalysis,it was showed that the number of flowers and larvae in inflorescence had the strongly direct effect on femalefitness, while the corolla tube length and corolla entrance diameter had less direct effect.【Conclusion】 It was indicatedthat thrips foraging was closely related to the floral traits of S. chamaejasme,such as flowering period and corollaentrance diameter,and its activity frequency had a significant effect on the female fitness of S. chamaejasme.