[Objectives]  To identify factors affecting the population dynamics of Bemisia tabaci (Gennadius) in Fujian province and thereby improve monitoring and control of this pest. [Methods]  Systematic surveys of B. tabaci populations in open fields and greenhouses were carried out in Zhangzhou and Jian’ou, sites in the northern and southern vegetable growing areas of Fujian, respectively. The effects of temperature on the development and fecundity of B. tabaci were evaluated in a laboratory. [Results]  B. tabaci were detected year-round in open fields in Zhangzhou. There were two population peaks; a summer peak from mid-June to mid-July and an autumn peak in mid-November. At Jian’ou B. tabaci were first observed in late March, with the summer population peak occurring in mid and late July, and the autumn peak in mid and late October. The developmental threshold temperature for eggs, 1st instar nymphs, 2nd instar nymphs, 3rd instar nymph and 4th instar nymphs were 13.77, 14.98, 9.60, 7.97 and 12.56 ℃, respectively, and the corresponding effective accumulated temperatures were 77.25, 29.13, 49.62, 65.03 and 65.13 degree-days, respectively. The annual number of generations in Jian’ou and Zhangzhou, deduced from weather data from 2015 to 2017, was 11-12 and 13-14, respectively. [Conclusion]  Temperature is a key factor affecting the population dynamics of B. tabaci and the optimal temperature range for the development of this pest was 21 to 27 ℃. Temperatures below 20 ℃, and above 30 ℃, were not suitable for development and reproduction. The laboratory population increased rapidly with increasing temperature when the 10-day^, average temperature was above 20 ℃. However, when the 10-day^, average temperature exceeded 30 ℃ it began to decline.