USer, please tell your jdev version!
The tree has a property disclosedRowKeys which holds all expanded (disclosed) rows (nodes). If your node is in the list you know it's expanded.
You can also use hte org.apache.myfaces.trinidad.event.RowDisclosureEvent to put some info in the node to make it easier to find out it's status.
Thanks for the reply Arun. But I want to find out the whether the node is expanded or collapsed. Based on the earlier mentioned result, I want to display different images . The image is no related to the table tree icon.