After studied something about importing various assets including video and audio files to a project of Premiere Pro, I tried to import some files as an exercise, but whenever I was selecting the directory not even pointing to the target file. The Premiere Pro crashed. This situation was repeatable. Then tried to update it to 5.5.2, but still same problem happened.
Upgrade OS X from 10.9 to 10.9.1
Using some other user account may avoid such crash. Don't know why.