diff --git a/block_test.go b/block_test.go
index 62d9a47..83ed2e1 100644
--- a/block_test.go
+++ b/block_test.go
@@ -1713,3 +1713,28 @@ func TestIsFenceLine(t *testing.T) {
 		}
 	}
 }
+
+func TestJoinLines(t *testing.T) {
+	input := `# 标题
+
+第一
+行文字。
+
+第
+二
+行文字。
+`
+	result := `<h1>标题</h1>
+
+<p>第一行文字。</p>
+
+<p>第二行文字。</p>
+`
+	opt := Options{Extensions: commonExtensions | EXTENSION_JOIN_LINES}
+	renderer := HtmlRenderer(commonHtmlFlags, "", "")
+	output := MarkdownOptions([]byte(input), renderer, opt)
+
+	if string(output) != result {
+		t.Error("output dose not match.")
+	}
+}
diff --git a/inline.go b/inline.go
index cb00ed6..c1f7475 100644
--- a/inline.go
+++ b/inline.go
@@ -170,6 +170,10 @@ func lineBreak(p *parser, out *bytes.Buffer, data []byte, offset int) int {
 	precededByBackslash := offset >= 1 && data[offset-1] == '\\' // see http://spec.commonmark.org/0.18/#example-527
 	precededByBackslash = precededByBackslash && p.flags&EXTENSION_BACKSLASH_LINE_BREAK != 0
 
+	if p.flags&EXTENSION_JOIN_LINES != 0 {
+		return 1
+	}
+
 	// should there be a hard line break here?
 	if p.flags&EXTENSION_HARD_LINE_BREAK == 0 && !precededByTwoSpaces && !precededByBackslash {
 		return 0
diff --git a/markdown.go b/markdown.go
index 58ba68d..09fc2d7 100644
--- a/markdown.go
+++ b/markdown.go
@@ -46,6 +46,7 @@ const (
 	EXTENSION_AUTO_HEADER_IDS                        // Create the header ID from the text
 	EXTENSION_BACKSLASH_LINE_BREAK                   // translate trailing backslashes into line breaks
 	EXTENSION_DEFINITION_LISTS                       // render definition lists
+	EXTENSION_JOIN_LINES                             // delete newline and join lines
 
 	commonHtmlFlags = 0 |
 		HTML_USE_XHTML |