I usually use "look Module::Name" from the cpan shell. Then you get a shell prompt and I either read the Makefile.PL, Build.PL, or execute it (which prints the deps to the terminal).
-Paul
Comment on Re: How to find the perl module's dependency modules ?
I can also see the dependency modules when I install a new perl module, but my expectation is any perl module is available to find the already installed module's dependency modules.