Hi Siew Fai Hoy,
The best approach here is as follows:
Your business object ( the underlying object to the row) should implement the INotifyPropertyChanged interface.
This will allow the RadGridView to automatically update the UI , when a property changes. This way any property visualized in the row , or bound to the business object should update automatically.
This will eliminate the need to search for a specific row visual and update it explicitly.
In case y have troubles implementing this, just let me know some more details on your specific scenario and I can prepare a few lines of code for you.
All the best,
the Telerik team