Then the new iPhoto version probably created a new iPhoto library.
Where is your iPhoto library located? Did you keep it in your "Pictures" folder or on an external drive?
Search your mac for other iPhoto libraries - type "Library6.iphoto" into the spotlight searchfield. DO you see more than one library there?
One more question, my photo stream only load photo that I took in October & Nov, not the older ones. Is that my photo stream has problem or what?
When you activate "Photo Stream" for a new library, it will download what is currently stored on the iCloud server, and that is limited to the last 30 days.
What your screenshot is showing, are the internal libraries in your current iphoto library. So it is not surprising, that the are both the same. Did you find only one "Library6.iPhoto"?
First thing to do, open the library itself, not the files inside.
Your screenshot is showing, that these files have been created and last opened a year ago. That cannot be your cureent library with all your pictures.
Open your "Pictures" folder and select the file "iPhoto Library" in that folder. What is the date there that you are seeing? Is the "last modified" newer?
Then try to find a different PhotoLibrary by holding down the alt/options ⌥ while double clicking that Photo Library. Do you see a panel with more library options to chose from?
First I have to sorry for wrong attachment. here's the right one
After I click Show Package Contents it's like this
I have searched for Library6.iPhoto but nothing appeared.
When I click on Library.iPhoto (or Library6.iPhoto) and do as you said (hold down Alt while double click it), it shows like this
But when I click on both of them, they are still the same.
Any other places that the old library can locate? Remember I modified nothing about location when installing it.
when you click the second "iPhoto Library" - not the (default) - does it show the same path in the bar below the window - is it really the same library in a different folder and not the Pictures folder?
You could try to search with a different tool for "Library6": Download Find Any File...
To search for all files, hold down the al/options key whwn selecting "Find".