I'm new in virtual tour creation. Please tell me how can i remove the tripod with APT?
I guess you mean APP or APG? (APT, Autopano Tour, was a predecessor of Panotour and Panotour Pro).
To remove the tripod from a pano image you will probably need a suitable nadir shot, or shots, which does not include the tripod.
Then most people choose to edit the nadir area using third-party software.
They convert the equirectangular (36-x180 FOV) pano image to cube faces and edit the nadir cube face. There are various tools that can be used to convert to cubefaces, or Pano2VR has a Patch tool that can extract a nadir area for editing and then re-incorporate it.
If the triopod 'footprint' is quite small and the nature of the nadir is suitable you can use an image editor clone/patch tool to edit it out.
Alternatively use your tripod-free nadir image(s) to cover the tripod.
Then convert the cube faces back to an equirectangular image.
If ultimately your stitched pano image is to be displayed online as part of a virtual tour then instead you may choose to limit the VFOV in the tour viewer , thereby hiding the nadir area; or most virtual tour authoring programs, such as Kolor's Panotour and Panotour Pro will also allow you to place a nadir patch image or logo over the nadir area, again hiding the tripod.