When moved contents from one site to another, some contents were not came in the list, what would be the reason?

DRUPAL would check the authorization while retreving the content.

Hence, if the author is not available in the site, it wouldn't show the associated content.

Ex:

Dev environment logins wont be available in QA environment.  Hence, it would be good to change the author name to admin or make it blank  while creating contents if planned to move the content.