diff --git a/gmtxy-image2.sh b/gmtxy-image2.sh
index cf2c4ee..5499d79 100755
--- a/gmtxy-image2.sh
+++ b/gmtxy-image2.sh
@@ -53,8 +53,9 @@ bar_origin=("0" "0")
 polyfile='null'
 lay_num=0
 run_command=1
+close_poly='-L'
 # 从命令行获取参数
-while getopts "hi:o:L:r:u:c:l:G:t:v:f:a:p:X:x:gnKOS" arg
+while getopts "hi:o:L:r:u:c:l:G:t:v:f:a:p:X:x:gnKOSP" arg
 do
 	case $arg in
 		h)
@@ -94,6 +95,7 @@ do
 				please output a data specified script using the -S option, then edit the script accordingly."
 			dispOptionShort "-p" "Take inputs from a table file and plot polygons. Each line of the file \
 				represents a 2D point's coordinates."
+			dispOptionShort "-P" "Keep the polygon plotted by the -p option open."
 			dispOptionShort "-K" "Keep the .ps file open. This option must be set for plotting multiple images to a single output file."
 			dispOptionShort "-O" "Continue from a previous .ps file. This option must be set for plotting multiple images to a single output file."
 			dispOptionShort "-X" "Move the starting point for mapping the image. Use this option for plotting sub-figures."
@@ -139,6 +141,8 @@ do
 			annotation=$OPTARG;;
 		p)
 			polyfile=$OPTARG;;
+		P)
+			close_poly='';;
 		K)
 			keep_open=1;;
 		O)
@@ -246,7 +250,7 @@ else
 
 	# 画多边形
 	if [[ $polyfile != 'null' ]]; then
-		RunOrEcho ${run_command} "gmt psxy ${polyfile} -JX${layouts[0]}/${pic_height}i -W0.25p,black,- -R${range} -L -K -O >> $psfile"
+		RunOrEcho ${run_command} "gmt psxy ${polyfile} -JX${layouts[0]}/${pic_height}i -W0.25p,black,- -R${range} ${close_poly} -K -O >> $psfile"
 	fi
 
 	#添加号码