Electrical transport measurements have been made on pure samples of HgTe at hydrostatic pressure up to 9 katm, in the temperature range 1.6-300 K and at magnetic fields up to 14 kG. Anomalies in the transport properties below 60 K have been observed. The possible models to account for this behavior have been discussed. For this reason the calculations of the concentration, using the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}}$ theory, and conductivity, in the case of resonant scattering, have been carried out for different parameters. Comparison of the calculated and experimental results does not give satisfactory agreements in all cases.