diff --git a/gmtsph-JA.sh b/gmtsph-JA.sh
index c9a4d22..db1c4ec 100755
--- a/gmtsph-JA.sh
+++ b/gmtsph-JA.sh
@@ -119,7 +119,7 @@ else
 	#-C${cptfile}+Uk 使用km（色标单位除1000
 	#如果unit等于km则在cptfile后面添加+Uk
 	if [[ ${unit} == 'km+Uk' ]]; then
-		gmt psscale -I -Dx0.85i/-0.2i+w1.5i/0.05i+h -C${cptfile}+Uk -Bxa -By+l${unit} -X-1.7i -O >> $psfile
+		gmt psscale -I -Dx0.85i/-0.2i+w1.5i/0.05i+h -C${cptfile}+Uk -Bxa -By+l"km" -X-1.7i -O >> $psfile
 	else
 		gmt psscale -I -Dx0.85i/-0.2i+w1.5i/0.05i+h -C${cptfile} -Bxa -By+l${unit} -X-1.7i -O >> $psfile
 	fi