Abstract: To determine the content of trehalose in transgenic Aloe by gas chromatography (GC),1-Methyl-imidazol,Hydroxylammonium chloride and Acetic anhydride were used to derivative the trehalose.The difference of the retention time among the same carbohydrate derivatives is 3s by this method.And it can separate the glucose,milk sugar,sucrose and trehalose clearly.The results showed a good linear relationship within a range from 3.697×10^-9　g to 28.661×10-9　g,and the liner correlation coefficient of the trehalose is 0.998　6.The content of trehalose in the three-year,five-year aloe (Aloe vera.L) and aloe transformed by ostA were determined by GC.The results show that the trehalose of the fiveyear aloe (Aloe vera.L) is 1.59 times as great as the three-year.The content of trehalose in five-year aloe is 1.103×10^-5　g per 10g,and 6.905×10^-6　g per 10g in three-year aloe.The content of trehalose is 1.614×10^-5　g per 10g in aloe transformed by ostA which is 2.33 times as great as the three-year aloe (Aloe vera.L).The results prove that the ostA gene from E.coli is successfully transformed to aloe and expressed.

Key words: gas chromatography, trehalose, quantificational analysis, Aloe vera.L