we had our lawn removed and had ground cover and now the weeds are growing in between the ground cover .how to prevent weeds from coming ?
You can't prevent them but once the groundcover becomes well established, it should significantly reduce their occurrence. In the meantime, you will have to remove them manually.
You will have to have to weed more during the time it takes to get the ground covers established. Mulching between the plants helps too.
Here is a link that might be useful: Perennial ground cover tips