[Objectives]  To determine changes in the basic cold tolerance of Liriomyza huidobrensis after undergoing rapid cold hardening (RCH), and to investigate the physiological and biochemical effects of RCH in this species. [Methods]  According to the results of a pilot study of temperature stress and acclimation time, the emergence rate of L. huidobrensis pupae was recorded after RCH acclimation and subsequently under low temperature stress (CS). A thermocouple was used to determine the supercooling point of acclimated and unacclimated pupae. GC-MS, HPLC-MS and spectrophotometer were used to determine the amount of fatty acids, sugars and glycerol in pupae under different temperature treatments. [Results]  The emergence rate of L. huidobrensis pupae increased significantly (20.00% to 45.60%)(F_{4, 10}=10.37, P<0.05) after RCH acclimation and subsequent exposure to low temperature stress but their supercooling point (SCP) did not change significantly (unacclimated: ﹣19.90 ℃, after acclimation: ﹣20.10 ℃)(t=0.703, P>0.05). After RCH, the content of palmitoleic acid increased (from 5.96% to 19.26%) (F_{3, 8}=52.717, P<0.05) whereas the content of palmitic acid decreased (from 24.32% to 2.94%) (F_{3, 8}=65.456, P<0.05). The ratio of total unsaturated fatty acids to saturated fatty acids increased (from 2.17 to 10.94) (F_{3, 8}=64.347, P<0.05). After acclimation, trehalose content increased (5.46 μg/mg to 7.71 μg/mg) (F_{3, 8}=9.912, P<0.05), glycerol content increased (from 1.177 μg/mg to 1.314 μg/mg) (F_{3, 8}=6.428, P<0.05) and glucose content decreased (from 1.84 μg/mg to 1.22 μg/mg) (F_{3, 8}=191.298, P<0.05). [Conclusion]  RCH in L. huidobrensis causes an increase in unsaturated fatty acids and cryoprotectants, including trehalose, glucose and glycerin.