Due to the sparsity of space probes, it is still not clear on how the magnetic structure of the magnetotail looks like and how it evolves when the interplanetary magnetic field (IMF) directs northward. This simulation study uses two different global magnetosphere magnetohydrodynamics (MHD) models to simulate two northward IMF events and study the evolution of the magnetotail. Both models show that the magnetotail may form a structure that is composed of a dawnside tail lobe and a duskside tail lobe, under northward IMF conditions with significant By, instead of a northern tail lobe and a southern tail lobe under southward IMF conditions. In this magnetic configuration, a tail lobe extends a domain from northern (southern) cusp to southern (northern) IMF. The larger the magnitude of IMF clock angle, the longer and wider the magnetotail. Such magnetic configuration suggests that magnetotail reconnection is possible to occur when the dawnside tail lobe contacts with the duskside tail lobe and thus a substorm is also possible to occur under northward IMF conditions with significant By. Plain Language Summary The Earth's magnetosphere is a vast space with certain magnetic structure and plasma material and is directly affected by solar wind and its embedded magnetic field named interplanetary magnetic field (IMF). Due to the sparsity of space probes, it is still not clear on how the magnetic structure of the magnetosphere looks like and how it evolves, especially when the IMF arriving the magnetosphere directs northward with a significant dawn‐dusk component, By. This simulation study uses two different global magnetosphere models to simulate the magnetosphere for two periods with northward IMF and show that the magnetotail (tail of magnetosphere) may form a structure that is composed of a dawnside tail lobe and a duskside tail lobe instead of a northern tail lobe and a southern tail lobe under southward IMF conditions. In this magnetic configuration, a tail lobe extends a domain from northern (southern) cusp to southern (northern) IMF. The larger the IMF By, the longer and wider the magnetotail. Such magnetic configuration suggests that magnetotail reconnection is possible to occur when the dawnside tail lobe contacts with the duskside tail lobe, and thus a substorm is also possible to occur under northward IMF conditions with significant By. Key Points A dawnside tail lobe and a duskside tail lobe may form in the magnetotail under northward interplanetary magnetic field (IMF) conditions with significant By The larger the magnitude of IMF clock angle, the longer and wider the magnetotail Magnetotail reconnection may occur when the dawnside tail lobe contacts with the duskside tail lobe, and is possible to cause substorm