Hi Hany 

Thanks for reaching out in the Lucidchart Community! If you completely close your account we will no longer be able to retrieve the documents you have created and saved to our systems. In this case I would recommend downloading and saving any documents you will need before closing your account.

However if you only cancel your subscription your account will automatically downgrade to a Free Account and we will then be able to retrieve your documents. In this case the documents will remain in your Free Account and you will still be able to view them. Since you will only have access to features available on Free accounts it's possible that you won't be able to edit with full functionally the documents you created using paid features. You should regain the ability to edit all of your documents at any time by resubscribing. 

To learn more about subscriptions' cancellations please take a look at our Renew or Cancel Your Subscription article from the Lucidchart Help Center. Hope this helps!