A new β-cyclodextrin(β-CD) derivative，2，6-di-O-pentyl-3-O-［(methyl)5 (allyl)2］-β-CD was synthesized.The chromatographic properties of this β-CD derivative were examined and studied by using as a chiral stationary phase in capillary gas chromatography，which showed a good separation ability and a chiral selectivity.Nine kinds of aromatic positional isomers were successfully separated with good resolutions，and parts of their separation results were better than that of 2，6-di-O-pentyl-3-O-allyl-β-CD and other β-CD derivatives.And meanwhile，more than ten kinds of chiral compounds were also determined on this stationary phase.Especially，the separations of some propanoic acid esters with α-substitute were better than those on heterocyclic β-CD derivatives reported in the literature.However，the experimental results showed the chiral separation ability of this stationary phase was still similar to the 2，6-di-O-pentyl-3-O-allyl-β-CD by comparison.It indicated that the introduction of methyl to the part of C3-OH positions may improve the selectivity to aromatic positional isomers，but could not affect obviously the chiral separation ability of the β-CD derivative modified allyl groups on the whole of the C3-OH positions.