Hi Matt , thanks for your reminder and answer , now i also have some confused thing:
1. There is one sentense : " Those files will be used to create an initial navigation when the portal is launched in the first time. That information will then be stored in the JCR content repository, and can then be modified and managed from the portal UI. " in this guide
https://docs.jboss.org/author/display/GTNPORTAL35/Portal+Navigation+Configuration
I use the <org.exoplatform.portal.version>3.0.0-GA</org.exoplatform.portal.version> so there is no importMode field in the class org.exoplatform.portal.config.NewPortalConfig .
I have tested , when i remove all of the tables of jcr and idm , the new page which i added to the configure files will work well , but then when i contine to add new page to the configure file and import it without removing the jcr tables , it doesn't work .
So i want to confirm with you about the verion 3.0.0-GA , does it only work when the portal is lanuched in the first time .