By using drift velocity data measured in the near-Earth tail lobe by the Electron Drift Instrument aboard the Cluster spacecraft, we study the average tail lobe convection of the Earth's magnetosphere. The data confirm the convection pattern toward the neutral sheet in the meridional (XZ) plane. By dividing the data according to the IMF clock angle, it is found that the convection direction in the plane perpendicular to the Sun-Earth line (YZ plane) are controlled by the IMF By component. It is understood in terms of the solar wind-induced electric field to the magnetotail lobe via dayside magnetic reconnection. For positive IMF Bz the average convection velocity is very low. For southward IMF, convection becomes strongest and a dawnward component appears.