Conducting polymer nanofibers/nanowires especially with an oriented arrangement have attracted great attention because of their unique properties and promising potentiality in nanomaterials and nanodevices, and increasing development for biomedical and biotechnological applications. For example, polyaniline (PANI) is one of the most useful conducting polymers due to its facile preparation, environmental stability, unique doping-dedoping property, and enhanced electrical performance. Herein, combining our recent research work, we have summarized and remarked the approaches developed for fabrication of one dimensional conductive nanofiber/nanowire in the article, mainly focusing on aligned or patterned arrays. The preparation processes have been classified as hard or soft template approach, step-wise electrochemical deposition, wet chemical polymerization, aqueous solution polymerization, interfacial polymerization, and electrospinning synthesis, and the formation mechanism of the polymer nanostructure in each process has been presented in detail. Additionally, some reaction parameters which play a dominant role on the size and shape of the products have been discussed in order to make one know the controlling conditions in that synthesis method. The aligned PANI nanofibers/nanowires, coupled with the useful functionalities of conducting materials, create both aesthetic beauty and scientific attractions. Accordingly, thin film nanofiber sensors can be made of the PANI nanofibers in many patents, having superior performance in both sensitivity and time response to a variety of gas vapors including hydrogen, acids, bases, redox active vapors, alcohols and volatile organic chemicals, as well as decontamination of chemical and biological agents by employing electrospun polymer nanofibers containing metal, metal oxides, metal oxide halogen adducts and mixtures thereof. New exciting applications of the polymer are expected to be discovered and novel synthesizing approaches are envisaged to be devised for the aligned polymer nanostructure based on the present summary.