Based on variations of the annual mean temperature and precipitation analyzed using observation data in Guyuan of Ningxia, the effects of climate change on the local flax developmental process and yield were investigated. The results showed that the annual mean temperature had an increasing trend (0.3 ℃·(10 a)^-1) and the annual precipitation had a decreasing trend (-20 mm·(10 a)^-1) from 1957 to 2012. While the increasing trend of mean temperature during growing season of flax was more obviously than that of the annual temperature, the decreasing trend of precipitation during growing season was similar to that of annual precipitation. With temperature increasing and precipitation decreasing, the flax development rate was accelerated, resulting in the reduced growing period. Seedling stage was advanced 0.7 d with 1 ℃ increase in temperature during the period from sowing to seedling emergence. The duration from seedling emergence to two pairs of needles was shortened by 0.8 d with 1 ℃ increase in temperature and 0.1 d with 1 mm decrease in precipitation. Maturity stage was advanced 1.8 d with 1 ℃ increase in temperature and 0.1 d with 1 mm decrease in precipitation during the period from technical maturity to maturity. The flax development was accelerated because of temperature increasing and precipitation decreasing in the vegetative growth phase, which was one of the main causes of flax yield reduction year by year. Meanwhile, flower bud differentiation and pollination of flax were influenced by temperature increasing in the reproductive growth phase, which would affect the number of capsules and the seed setting rate per plant and lead to the decrease of flax yield. Therefore, adjusting plant structure and enlarging the planting area of late or middlelate variety were the important measures to reduce the effects of climate change on local flax production.