A mathematical model representing the relation between pulling up speed, time and aspect ratio is reported, accordingly the axially pull-up electrochemical etching method for fabricating nanoprobes is proposed. The tungsten probes with predetermined shape and aspect ratio according to the model were successfully produced with this method. Then the probes were installed inside a micromanipulation system to manipulate the carbon nanotubes and measure their current-voltage (I-V) characteristics. The probe fabrication and application experiments demonstrated the reasonability and reliability of the model and method developed in this note.