Electrospun material with bio-inspired ordered architectures and patterns is very interesting, yet remains a challenge. We report here that nanofibrous mats with bird's nest patterned structures can be directly electrospun from chlorinated polypropylene solutions doped with an ionic liquid. The solution viscosity and the ionic liquid content are two dominant factors to influence the topological morphology of the nanofibrous mats. The patterned structures can be further modulated by the collection time of electrospinning, the humidity of environment and the design of collector. We suggest the electrostatic repulsion between the residual charges of the mat surface and the upcoming nanofibers plays a key role in the formation of the bird's nest patterns.