Many interesting physical properties of graphene have been identified and investigated within the framework of massless relativistic fermions. When one stacks graphene layers on top of each other, modification of the physical properties occurs in an unexpected way. In this presentation, I will discuss our computational efforts that investigate the special electronic properties of twisted bilayer graphene (TBG). We have systematically mapped out the spectra of these Landau levels (LLs) as a function of the rotational angle and provided quantitative predictions of the fractal spectra in a certain angular range. In addition, the time-dependent wave-packet propagation demonstrates an anisotropic dynamical behavior of electrons in TBG, which is related to the specific interlayer coupling.