I have a child theme from Genesis framework. How can I create a child theme of it. Actually I need to do some changes, so if I'm changing in my child theme, then if any future updates comes I can not update. Is there any way?
If it's normal child theme then creating so called "grand child" theme for it is not natively supported by WordPress.
You should look into customization options offered by framework, since that is typical for the case. Please note that since Genesis code is behind paywall and not publicly available it's not considered in scope here.
It just isn't supported out of the box. WP-Code Snippets has an example on how to make this work though by creating it as a plugin.
I've never tested this, so I can't verify if it still works (it was written in 2012), but I don't see why not. Appthemes has a more in-depth tutorial on how to create grandchild themes as a plugin.