Thank you Raphy. I Know this method, but it's manuel

I'm looking for automated one in which I can import quantity data from Excel file.

Regards 

Hi,

Are you looking to import the initial inventory directly to the Product Master ? If so, it is not the way to do it. Instead you have to create an inventory adjustment for this purpose and give the name as opening balance/initial inventory.

Navigate to Inventory -> Operations -> Inventory Adjustments

Enter the Qty's after clicking the Continue Inventory button.

Then Click on Save and then Validate Inventory.

See this Odoo Documentation: Set your Initial Stock in Odoo

Reference: How to Setup the Initial Inventory in Odoo

Thanks