how i can do the following : when the user click on some cell : EX: cell(3) of the current datagridview onther datagridview appear and when the user select row from the second datagridview the seleceted row information on cell(4) and cell (5) .

someone help plz???

Hi
It sounds like you want to create a master / details view using two datagrids? Here is an example MSDN Example although this has each one statically displayed on a form.

I think what you will have to do is create a data set with your "master" data and your "Sub" data and define a relationship between them as in the example above BUT only have one datagridview displayed and when the user clicks on it display a second grid using the results of a lookup via the relationship.