diff --git a/trunk/research/hls/check_hls_backup.sh b/trunk/research/hls/check_hls_backup.sh
new file mode 100755
index 000000000..45f0ef10f
--- /dev/null
+++ b/trunk/research/hls/check_hls_backup.sh
@@ -0,0 +1,99 @@
+if [[ $# -lt 2 ]]; then
+    echo "Usage: $0 <hls0> <hls1> [keep_ts]"
+    echo "      keep_ts to keep the download ts, default is off"
+    echo "For example:"
+    echo "      $0 http://192.168.1.137:1980/hls/live/stone/live.m3u8 http://192.168.1.137:1984/hls/live/stone/live.m3u8"
+    echo "      $0 http://192.168.1.137:1980/hls/live/livestream/live.m3u8 http://192.168.1.137:1984/hls/live/livestream/live.m3u8"
+    echo "      $0 http://ossrs.net:1984/hls/live/livestream/live.m3u8 http://ossrs.net:1996/hls/live/livestream/live.m3u8"
+    exit 1
+fi
+ 
+hls0=$1
+hls1=$2
+keep_ts=NO
+if [[ $# -gt 2 ]]; then
+    keep_ts=YES
+fi
+#echo "check hls backup of $hls0 vs $hls1, keep_ts=$keep_ts"
+
+hls0_tss=`curl $hls0 2>/dev/null |grep "\.ts"`
+hls1_tss=`curl $hls1 2>/dev/null |grep "\.ts"`
+
+hls0_prefix=`dirname $hls0`
+hls1_prefix=`dirname $hls1`
+work_dir="./hbt_temp_`date +%s`"
+
+md5_tool="md5"
+`md5sum --version >/dev/null 2>&1` && md5_tool="md5sum"
+#echo "use md5 tool: $md5_tool"
+
+CHECKED=NO
+OK=YES
+for ts in $hls0_tss; do
+    match=NO
+    for ts1 in $hls1_tss; do
+        if [[ $ts == $ts1 ]]; then
+            #echo "check ts $ts"
+            match=YES
+            break
+        fi
+    done
+    #echo "check ts $ts, match=$match"
+    
+    if [ $match = NO ]; then
+        echo "skip $ts"
+        continue
+    fi
+    
+    ts0_uri=$hls0_prefix/$ts
+    ts1_uri=$hls1_prefix/$ts
+    ts0_tmp=$work_dir/hls0/`basename $ts`
+    ts1_tmp=$work_dir/hls1/`basename $ts`
+    #echo "start check $ts0_uri($ts0_tmp) vs $ts1_uri($ts1_tmp)"
+    
+    mkdir -p `dirname $ts0_tmp` &&
+    curl $ts0_uri >$ts0_tmp 2>/dev/null &&
+    ret=$?; if [[ $ret -ne 0 ]]; then echo "download $ts0_uri to $ts0_tmp failed. ret=$ret"; exit $ret; fi
+    
+    mkdir -p `dirname $ts1_tmp` &&
+    curl $ts1_uri >$ts1_tmp 2>/dev/null &&
+    ret=$?; if [[ $ret -ne 0 ]]; then echo "download $ts1_uri to $ts1_tmp failed. ret=$ret"; exit $ret; fi
+    
+    if [[ $md5_tool == "md5" ]]; then
+        ts0_cs=`$md5_tool $ts0_tmp|awk '{print $4}'`
+    else
+        ts0_cs=`$md5_tool $ts0_tmp|awk '{print $1}'`
+    fi
+    #echo "hls0: md5sum($ts0_tmp)=$ts0_cs"
+    
+    if [[ $md5_tool == "md5" ]]; then
+        ts1_cs=`$md5_tool $ts1_tmp|awk '{print $4}'`
+    else
+        ts1_cs=`$md5_tool $ts1_tmp|awk '{print $1}'`
+    fi
+    #echo "hls1: md5sum($ts1_tmp)=$ts1_cs"
+    
+    if [[ $ts0_cs != $ts1_cs ]]; then
+        echo "$ts0_uri($ts0_cs) not equals to $ts1_uri($ts1_cs)"
+        OK=NO
+    fi
+    CHECKED=YES
+done
+
+if [ $keep_ts = NO ]; then
+    #echo "clenaup work dir $work_dir"
+    rm -rf $work_dir
+else
+    echo "keep work dir $work_dir"
+fi
+
+#echo "====================================================="
+if [[ $OK = YES && $CHECKED = YES ]]; then
+    echo "OK"
+    exit 0
+else
+    echo "FAILED"
+    exit 1
+fi
+
+exit 0
\ No newline at end of file