Thank for all person upstairs.
The problem is the version of php.
When I use php5.3.2 and use phpinfo() look the information,there report jpeg is enable.
But ecshop reports unsupport.
Today I change my php to 5.2.10.
Now It`s OK.
Code:
Operatingsystem..........................................................................................................................Linux
PHPversion..........................................................................................................................5.2.10
SupportMySQL?..........................................................................................................................Support
GDversion..........................................................................................................................2
SupportJPEG?..........................................................................................................................Support
SupportGIF?..........................................................................................................................Support
SupportPNG?..........................................................................................................................Support
Importantfileintegrity?..........................................................................................................................Integrity
Safemode?..........................................................................................................................No