We have imported the simple product using
system -> Import/Export -> Dataflow profile -> Import All Products
We want to associate this product with configurable product. How we will achieve this?
Data flow doesn't support simple products association, you can use import/export instead it's available since magento 1.5
System > Import/Export > Import
Read this article to get more details on how to generate the csv: http://www.magestore.com/how-to-magento-import-configurable-products.html/