diff --git a/R/group_rows.R b/R/group_rows.R
new file mode 100644
index 0000000..9827811
--- /dev/null
+++ b/R/group_rows.R
@@ -0,0 +1,51 @@
+#' Put a few rows of a table into one category
+#'
+#' @export
+group_rows <- function(kable_input, group_label, start_row, end_row) {
+  kable_format <- attr(kable_input, "format")
+  if (!kable_format %in% c("html", "latex")) {
+    message("Currently generic markdown table using pandoc is not supported.")
+    return(kable_input)
+  }
+  if (kable_format == "html") {
+    return(group_rows_html(kable_input, group_label, start_row, end_row))
+  }
+  if (kable_format == "latex") {
+    return(group_rows_latex(kable_input, group_label, start_row, end_row))
+  }
+}
+
+group_rows_html <- function(kable_input, group_label, start_row, end_row) {
+  if (!is.numeric(c(start_row, end_row))) {
+    stop("Start_row and end_row must be numeric position of rows (excluding",
+         "header rows and other group-title rows). ")
+  }
+  kable_attrs <- attributes(kable_input)
+  kable_xml <- read_xml(as.character(kable_input), options = "COMPACT")
+  kable_tbody <- xml_tpart(kable_xml, "tbody")
+
+  group_header_rows <- attr(kable_input, "group_header_rows")
+  group_seq <- seq(start_row, end_row)
+  if (!is.null(group_header_rows)) {
+    group_seq <- positions_corrector(group_seq, group_header_rows,
+                                     length(xml_children(kable_tbody)))
+  }
+
+  # Insert a group header row
+  starting_node <- xml_child(kable_tbody, group_seq[1])
+  kable_ncol <- length(xml_children(starting_node))
+  group_header_row_text <- paste0(
+    '<tr groupLength="', length(group_seq), '"><td colspan="',
+    kable_ncol, '"><strong>', group_label, "</strong></td></tr>"
+  )
+  group_header_row <- read_xml(group_header_row_text, options = "COMPACT")
+  xml_add_sibling(starting_node, group_header_row, .where = "before")
+
+  # add indentations to items
+  out <- structure(as.character(kable_xml), format = "html",
+                   class = "knitr_kable")
+  attributes(out) <- kable_attrs
+  attr(out, "group_header_rows") <- c(attr(out, "group_header_rows"), group_seq[1])
+  out <- add_indent(out, positions = seq(start_row, end_row))
+  return(out)
+}