diff --git a/demo/mushroom/dump2json.py b/demo/mushroom/dump2json.py
new file mode 100755
index 000000000..dae506457
--- /dev/null
+++ b/demo/mushroom/dump2json.py
@@ -0,0 +1,80 @@
+#!/usr/bin/python
+import sys
+import json
+
+def loadnmap( fname ):
+    nmap = {}
+    for l in open(fname):
+        arr = l.split()
+        nmap[int(arr[0])] = arr[1].strip()
+    return nmap
+
+def recstats( rec, l, label ):
+    for it in l.split(','):
+        k = int( it )
+        if k not in rec:
+            rec[ k ] = (0,0)
+        else:
+            if label == 0:
+                rec[k] = (rec[k][0]+1,rec[k][1])
+            else:
+                rec[k] = (rec[k][0],rec[k][1]+1)
+
+def loadstats( fname, fpath ):
+    res = {}
+    fp = open( fname )
+    for l in open( fpath ):
+        label = int( fp.readline().split()[0] )
+        arr = l.split()
+        for i in xrange( len(arr) ):
+            if i not in res:
+                res[ i ] = {}
+            recstats( res[ i ], arr[i], label )            
+    return res
+
+def mapid( idmap, fid, bid ):
+    if (bid, fid) not in idmap:
+        idmap[ (bid,fid) ] = len(idmap)
+    return idmap[ (bid,fid) ]
+
+def dumpjson( fo, trees ):
+    fo.write('{\n')
+    fo.write('  \"roots\":'+json.dumps( trees['roots'], separators=(' , ',' : ') ) +',\n' )
+    fo.write('  \"weights\":'+json.dumps( trees['weights'], separators=(' , ',' : ') ) +',\n' )
+    fo.write('  \"nodes\":[\n' )
+    fo.write('%s\n   ]' % ',\n'.join(('    %s' % json.dumps( n, separators=(' , ',' : ') ) )   for n in trees['nodes']) )
+    fo.write('\n}\n')
+        
+fo = sys.stdout
+nmap = loadnmap( 'featname.txt' )
+stat = loadstats( 'agaricus.txt.test', 'dump.path.txt' )
+
+trees = {'roots':[], 'weights':[], 'nodes':[] }
+idmap = {}
+
+for l in open( 'dump.txt'):
+    if l.startswith('booster['):
+        bid = int( l.split('[')[1].split(']')[0] )
+        trees['roots'].append( mapid(idmap,bid,0) )
+        trees['weights'].append( 1.0 )
+        continue
+
+    node = {}
+    rid = int( l.split(':')[0] )
+    node['id'] = mapid( idmap, bid, rid )
+    node['neg_cnt' ] = stat[ bid ][ rid ][ 0 ]
+    node['pos_cnt' ] = stat[ bid ][ rid ][ 1 ]       
+
+    idx = l.find('[f')
+    if idx != -1:
+        fid = int( l[idx+2:len(l)].split('<')[0])
+        node['label'] = nmap[ fid ]
+        node['children'] = [ mapid( idmap, bid, int(it.split('=')[1]) ) for it in l.split()[1].split(',') ]
+        node['edge_tags'] = ['yes','no']
+    else:
+        node['label'] = l.split(':')[1].strip()
+        node['value'] = float(l.split(':')[1].split('=')[1])
+
+    trees['nodes'].append( node )
+trees['nodes'].sort( key = lambda x:x['id'] )
+dumpjson( sys.stderr, trees)
diff --git a/demo/mushroom/runexp.sh b/demo/mushroom/runexp.sh
index 16747b15e..f4ae9c5e2 100755
--- a/demo/mushroom/runexp.sh
+++ b/demo/mushroom/runexp.sh
@@ -3,5 +3,4 @@ python mapfeat.py
 python mknfold.py agaricus.txt 1
 ../../xgboost mushroom.conf
 ../../xgboost mushroom.conf task=dump model_in=0003.model
-../../xgboost mushroom.conf task=dumppath model_in=0003.model 
 python maptree.py