We investigate transport properties of electrons through an asymmetric T-shaped magnetic quantum structure by the mode-mathcing technique and solution of the single electron Schrdinger equation. The results show that the changes of structural factors and magnetic field affect the electron scattering behavior and result in various patterns of electron transmission. When different magnetic configurations and structural factors are used, the transmission exhibits various patterns such as wide valley, sharp peak, resonant reflection, resonant transmission, and so on. Our results show that one may control the transmission property to design interferential quantum devices by adjusting magnetic configurations and or structural parameters.