  We study the dependence of thermal conductivity of single walled nanotubes
(SWNT) on chirality, isotope impurity, tube length and temperature by
nonequilibrium molecular dynamics method with accurate potentials. It is found
that, contrary to electronic conductivity, the thermal conductivity is
insensitive to the chirality. The isotope impurity, however, can reduce the
thermal conductivity up to 60% and change the temperature dependence behavior.
We also found that the tube length dependence of thermal conductivity is
different for nanotubes of different radius at different temperatures.
