mahmoud_bh:
i have an ethercard and a micro sd card modules
so the problem is i cant connect both of them to a single arduino uno because they need the same pins 11/12/13
That suggests that both devices use SPI and if so they can share those pins - that is the whole purpose of SPI.
However you need to post links to the datasheets for the devices if you need confirmation of that.
...R