Where can I find old R packages in .zip format ?
At CRAN for example : http://cran.r-project.org/src/contrib/Archive/shapefiles
there are only sources of .tar.gz files, I have to install old version of shapefiles because some finctions have been removed.
Package sources were only ever supplied in tar.gz compressed archives. Other archives (eg .zip) were binary packages for Windows or MacOS X. CRAN doesn't keep binaries for older versions of packages nor does it keep them for Archived packages, as per its policy.
If you are looking for a pre-built binary then you will either have to build one yourself, or if you are on Windows, you could use the win-builder service to build a Windows binary for you, but you'll need to make sure you change the maintainer details so you get a response and make sure you are allowed by the licence to re-distribute the sources in the manner you are doing. Do note all the caveats on that page before submitting!