Hi, I imported my active directory profiles to my SharePoint SharedServices successfully. Later on I updated user information (mobile number) of a user then I started full import and even did incremental import. but when I see in user profile information mobile number is not getting updated. Even I did gpupdate and iisreset still it is not updating

Is the User Profile property "Mobile Number" (correctly) mapped to the corresponding field in the Active Directory you're synching with? By default, this field is not mapped. You can specify the mapping in SharedServices Admin under User Profile and Properties > View Profile Properties > User Profile Property (http://yoursspsite/ssp/admin/_layouts/EditProperty.aspx?Name=CellPhone&IsSection=False) Hope this helps!