  We evaluate the multiplicity of hadrons in the $e^+e^-$-annihilation at a
given thrust $T$ in the modified leading-log approximation, including
$O(\sqrt{\alpha_s})$ corrections. The calculation is done at a large value of
$\tau =1-T$ by the use of the factorisation which takes place in the
one-particle-inclusive cross section at a given $\tau$. At a small $\tau$, a
different type of factorisation takes place, which also enable us to evaluate
the multiplicity. Two approaches are compared numerically. Measuring this
quantity near $\tau =1/3$, we can determine the multiplicity ratio between a
gluon-jet and a quark-jet.
