Well-ordered, globally oriented composite fibers with micro/nanowire arrays of polystyrene (PS) fibers embedded in polymethylmethacrylate (PMMA) were prepared by an iterative melt co-drawing and the bundling technique. With section-cutting of the PMMA/PS fiber and the dissolution of inner PS, porous PMMA template were obtained. In this approach, the three dimensional geometric parameters of the porous array PMMA template can be tuned over a large range, from micron- to nano-scale. Optical microscopy and scanning electron microscopy (SEM) showed that the distribution of pores were regular hexagonal, owing to the excellent match of rheology properties of the materials and appropriate control of the experimental condition. The diameters of the pores were several microns and the spacings of pores were several tens microns after the second drawing step, the diameters of the pores after the third drawing step were about 300 nm, and the spacings of pores were 2-3 micron. The porous PMMA template with other geometric parameters were also obtained in the experiment. There was good agreement between calculated and experimental values for the pore diameters and spacings. The obtained porous PMMA template was used to prepare metal micro/nanowires by electrochemical deposition. SEM in combination with the energy dispersive X-ray analysis (EDX) indicated that Cu micro/nanowires were successfully deposited in the pores of the template. The Cu micro/nanowire arrays were obtained after the dissolution of PMMA. Potential applications of this simple and inexpensive fabrication technology were discussed for preparing micro/nanowire arrays with highly controllable geometric parameters. And it may greatly improve the ability to design and construct a variety of micro/nano array materials according to the application requirements. (E-mail: phil_yang1005@sina.com) Keywords: porous polymethylmethacrylate template, melt co-drawing, size control, micro/nanowire arrays