  A prototype of a new CsI(Tl) telescope, which will be used in the reaction
studies of light isotopes with energy of several hundred AMeV, has been
constructed and tested at the Institute of Modern Physics, Chinese Academy of
Sciences. The telescope has a multi-layer structure and the range information
will be obtained to improve the particle identification performance. This
prototype has seven layers of different thickness. A 5.0% (FWHM) energy
resolution has been extracted for one of the layers in a beam test experiment.
Obvious improvement for the identification of $^{14}$O and $^{15}$O isotopes
was achieved by using the range information.
