  We present the results of an age determination study of pre-main sequence
stars in the Taurus star-forming region. The ages of 10 single stars with
masses of 0.5-1.1 Msun were derived from the surface gravities, estimated from
high-resolution optical and near-infrared spectroscopy. The equivalent width
ratios of nearby absorption line pairs were employed for the surface gravity
diagnostic, which directly reflects the parameters of the stellar atmosphere
without any veiling correction. From a comparison of determined ages and
near-infrared color excesses such as J-H, J-K, and J-L, the inner disk lifetime
of the young stars with 0.5-1.1 Msun in Taurus is estimated to be 3-4 Myr.
