Dynamic mechanical measurements were made in order to investigate effects of the drawing conditions on the viscoelastic properties of PET filament yarns at low temperatures(-100$^{circ}$C∼-0$^{circ}$C). The tan$delta$-temperature relations of the Maxwell and the Zener model were theoretically plotted and compared with the experimental data. It was shown that the experimental results nearly coincided with the Maxwell model at temperatures below the ${eta}$ peak and with the Zener model in the neighbor of the ${eta}$ peak. Maximum tan$delta$ at the ${eta}$ peak decreased with the increase of the drawing temperature but was not affected by the draw ratio. On the other hand maximum tan$delta$ temperature at the ${eta}$ peak was not significantly affected by the drawing temperature and the draw ratio.