Mature fruits of Guoqing No.1 and No.3 satsuma mandarins (Citrus unshiu Marc.) were stored under 4 ℃ and ambient temperature.Limonin and naringin contained in pulp of the fruits were determined during storage by high performance liquid chromatography.Results showed that:nomilin was under detection level in the pulp,while naringin content was 10 times as much as limonin upon harvesting.Irrelevant to storage temperatures,contents of limonin and naringin in both cultivars increased in a general aspect,but changes were much acute for fruits stored under4℃ comparing with those in ambient temperature.Furthermore,storage under 4 ℃ inducing significant content changes of limonin and naringin in pulp of Guoqing No.1 at several stages,thus,Guoqing No.1 was assumed to be more sensitive to the low temperature than Guoqing No.3.Low temperature as 4℃ stimulated the increase of bitterness content,especially in limonin,while 0-20 d was the sensitive period after storage.