Abstract: The possible physiological mechanism of enhancement of cold tolerance by salicylic acid(SA)in banana seedlings(Musa A L．CV．Williams 8188)was explored．1 d of 0.3—0.9 mmol·L^-1 SA treatment at 22/15 ℃ by spayed to leaves and irrigated to roots of banana seedlings)significantly enhanced chilhng-resistance of banana seedlings during subsequent 7 ℃ or 5 ℃ low temperature stress， indicated by the reduction of electrolyte leakage or wilting aIea，respectively．Under normal growth condition(22/15 ℃)，1 d of0．5 mmol·L^-1 treatment eaused a slight decrease of Fv/Fm，Fv’/Fm’，qP，卯S1I and Pn．However，SA pretreatment markedly inhibited the reduction of Fv/Fm, Fv’/Fm’,qP，卯SⅡ and Pn，and alleviated the rapid increase of Fo and NPQ during 3 d of 7 ℃ low temperature．And during 2 d of recovery periods(22/15%：)，SA pretreattment also accelerated the recovery of these photosynthetic parameters above．Th e results indicated that SA pretreatment could provide a protection for the cell membranes and the photosynthetic functions of the cold-stIIessed banana see(uirlgs， which could help to enhance thechiling tolerance of banana plants．

Key words: Banana, Salicylic acid, Low temperature, Electrolyte leakage, Photosynthetic functions