  Collapse and fragmentation of primordial filamentary clouds under isotropic
dissociation radiation is investigated with one-dimensional hydrodynamical
calculations. We investigate the effect of dissociation photon on the
filamentary clouds with calculating non-equilibrium chemical reactions. With
the external radiation assumed to turn on when the filamentary cloud forms, the
filamentary cloud with low initial density ($n_0 \le 10^2 \mathrm{cm^{-3}}$)
suffers photodissociation of hydrogen molecules. In such a case, since main
coolant is lost, temperature increases adiabatically enough to suppress
collapse. As a result, the filamentary cloud fragments into very massive clouds
($\sim 10^5 M_\odot$). On the other hand, the evolution of the filamentary
clouds with high initial density ($n_0>10^2 \mathrm{cm^{-3}}$) is hardly
affected by the external radiation. This is because the filamentary cloud with
high initial density shields itself from the external radiation. It is found
that the external radiation increases fragment mass. This result is consistent
with previous results with one-zone models. It is also found that fragment mass
decreases owing to the external dissociation radiation in the case with
sufficiently large line mass.
