To study the turbulent structure of on unsteady isothermal and nonisothermal gas flow in a tube the measurements methods are devised and experimental data on the profiles of the longitudinal and radial velocity components are received. The two-hot wire X-shaped mobile probe of constant temperature was used. The results of the profiles of the longitudinal and radial velocity components , their pulsations, the temperature pulsations, their correlations and heat transfer under gas flow acceleration and deceleration conditions are presented. These parameters in the unsteady processes are shown to differ noticeably from their quasi-steady values.