The largest any single dimension can be 1024, the largest total work-items per group is 1024.
So if you have X dimension of 1024, then Y and Z must be 1.
Basically, the product of all dimensions must be <= Max work group size.
 fixed typo, work-item per thread ==> work-item per group
Ok that i understood but how many work groups can be created each have 10 x 10 x 10 work items in it( <1024)
Can i have 1000,1000,1000 work groups < 2^32 -1 (address bit in my device is 32)
and each of this work group having 10,10,10 work items
Is this ok???????
yes. number of work group is practicali unlimited or it is limited by maximum of work items.