Thank you,
but set style height 100% not work.
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Test Texbox Multiline Height 100%</title>
<link rel="stylesheet" type="text/css" href="https://www.jeasyui.com/easyui/themes/default/easyui.css">
<link rel="stylesheet" type="text/css" href="https://www.jeasyui.com/easyui/themes/icon.css">
<link rel="stylesheet" type="text/css" href="https://www.jeasyui.com/easyui/themes/color.css">
<link rel="stylesheet" type="text/css" href="https://www.jeasyui.com/easyui/demo/demo.css">
<script type="text/javascript" src="https://code.jquery.com/jquery-1.9.1.min.js"></script>
<script type="text/javascript" src="https://www.jeasyui.com/easyui/jquery.easyui.min.js"></script>
</head>
<body>
<div style="width: 400px; height: 400px; padding: 10; border: 1px;">
<div id="pNoteCkin" class="easyui-panel" title="Check-In Note" data-options="fit:true" style="background-color: #e8f0ff;">
<form id="fNoteCkin" name="item_note_ckin" method="post">
<input id="ttNoteCkin" name="ttNoteCkin" class="easyui-textbox" multiline="true" style="width:100%; height:100%;" />
</form>
</div>
</div>
</body>
</html>