Embodiments of the present disclosure disclose a method of positioning and a corresponding portable device. In one embodiment, a method of positioning is provided. The method comprises: capturing, by image capturing equipment of a portable device, a visually encoded to in an environment; decoding the visually encoded tag to obtain an identification for generating the visually encoded tag; and determining a location of the portable device in the environment by querying a predefined library using the identification, the library recording correspondences between a set of identifications for generating visually encoded tags and a set of locations in the environment.