“Cool island” effect is a major aspect in oasis effect. This thesis has retrieved the Land Surface Temperature (LST) of Yutian area in the southern marginal zone of Tarim Basin in 1989, 1999 and 2002; constructed the Oasis-Cold-Island Ratio Index; established the west to east and the north to south temperature profiles taking the Yutian county as the centre; has quantitatively analyzed the spatial-temporal change of “cool island” effect in interior Yutian oasis for 14 years; pointed out “the cool island effect” has the weaker tendency in Yutian oasis; and through the analysis to Yutian temperature field, summarized the representation aspects of the space variation of “the cool island effect”: ①the expansion of Yutian county has weakened the intensity and the scope of “cool island effect”; ②in Yutian county, the interior temperature gradient changes slightly and the temperature fluctuation becomes slower.