That does not seem to the the script, see get vs. put.
Can you please post a matching log and script pair?

Anyway, such script can easily generate group-only XML log. The only command that generates some actual output is get. And that may still generate no output, when there are no files to download.

option echo on
option batch abort
option confirm off
open sftp://*****:*****@******:22
lcd D:\ERPFTP\NOREV\OUTPUT
cd Inbox
get -resume *
exit

Can you post your script?

I try several times about the XML logging,
every time the log file was generated only with Group elements but without sub elements under the group elements ,normaly there should be other elements like the result of each operation,how can i get this kind of info in the log?
Version:WinSCP 5.1.3
Scirpt :
WinSCP.com /script=D:\ERPFTP\scripts\NOREV\download_script.txt /xmllog=D:\ERPFTP\logs\NOREV\results\download_%date:~5,2%%date:~8,2%%time:~0,2%%time:~3,2%.xml /xmlgroups
XML log:
<?xml version="1.0" encoding="UTF-8"?>
<session xmlns="https://winscp.net/schema/session/1.0" name="MZPB9601@mts2.mpsa.com" start="2013-01-24T02:00:01.428Z">
<group name="sftp://MZPB9601:***@mts2.mpsa.com:22" start="2013-01-24T02:00:11.584Z">
</group>
<group name="lcd D:\ERPFTP\NOREV\INPUT" start="2013-01-24T02:00:11.584Z">
</group>
<group name="cd MZPB9601" start="2013-01-24T02:00:11.584Z">
</group>
<group name="put * " start="2013-01-24T02:00:11.584Z">
</group>
<group name="exit " start="2013-01-24T02:00:11.584Z">
</group>
</session>