直接的两个办法，比较麻烦，但是易懂.......
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3c.org/TR/1999/REC-html401-19991224/loose.dtd">
<HTML><HEAD><TITLE>Rounded Box Demo</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<STYLE type=text/css>
BODY {
PADDING-RIGHT: 0px; PADDING-LEFT: 0px; FONT-SIZE: 16px; PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-TOP: 0px; FONT-FAMILY: Georgia; BACKGROUND-COLOR: #fff
}
DIV.rounded-box {
MARGIN: 3px; WIDTH: 9em; POSITION: relative; BACKGROUND-COLOR: #e6e6e6; filter:Alpha(Opacity=50);
}
DIV.top-left-corner {
OVERFLOW: hidden; WIDTH: 20px; POSITION: absolute; HEIGHT: 20px; BACKGROUND-COLOR: #fff
}
DIV.bottom-left-corner {
OVERFLOW: hidden; WIDTH: 20px; POSITION: absolute; HEIGHT: 20px; BACKGROUND-COLOR: #fff
}
DIV.top-right-corner {
OVERFLOW: hidden; WIDTH: 20px; POSITION: absolute; HEIGHT: 20px; BACKGROUND-COLOR: #fff
}
DIV.bottom-right-corner {
OVERFLOW: hidden; WIDTH: 20px; POSITION: absolute; HEIGHT: 20px; BACKGROUND-COLOR: #fff
}
DIV.top-left-inside {
FONT-SIZE: 150px; COLOR: #e6e6e6; LINE-HEIGHT: 40px; FONT-FAMILY: arial; POSITION: relative
}
DIV.bottom-left-inside {
FONT-SIZE: 150px; COLOR: #e6e6e6; LINE-HEIGHT: 40px; FONT-FAMILY: arial; POSITION: relative
}
DIV.top-right-inside {
FONT-SIZE: 150px; COLOR: #e6e6e6; LINE-HEIGHT: 40px; FONT-FAMILY: arial; POSITION: relative
}
DIV.bottom-right-inside {
FONT-SIZE: 150px; COLOR: #e6e6e6; LINE-HEIGHT: 40px; FONT-FAMILY: arial; POSITION: relative
}
DIV.top-left-corner {
LEFT: 0px; TOP: 0px
}
DIV.bottom-left-corner {
LEFT: 0px; BOTTOM: 0px
}
DIV.top-right-corner {
RIGHT: 0px; TOP: 0px
}
DIV.bottom-right-corner {
RIGHT: 0px; BOTTOM: 0px
}
DIV.top-left-inside {
LEFT: -8px
}
DIV.bottom-left-inside {
LEFT: -8px; TOP: -17px
}
DIV.top-right-inside {
LEFT: -25px
}
DIV.bottom-right-inside {
LEFT: -25px; TOP: -17px
}
DIV.box-contents {
PADDING-RIGHT: 8px; PADDING-LEFT: 8px; PADDING-BOTTOM: 8px; COLOR: #000; PADDING-TOP: 8px; POSITION: relative
}
</STYLE>
<META content="MSHTML 6.00.2800.1106" name=GENERATOR></HEAD>
<BODY>
<DIV class=rounded-box>
<DIV class=top-left-corner>
<DIV class=top-left-inside>•</DIV></DIV>
<DIV class=bottom-left-corner>
<DIV class=bottom-left-inside>•</DIV></DIV>
<DIV class=top-right-corner>
<DIV class=top-right-inside>•</DIV></DIV>
<DIV class=bottom-right-corner>
<DIV class=bottom-right-inside>•</DIV></DIV>
<DIV class=box-contents>Contents go here, but it must be at least two lines to
look any good. </DIV><!-- end div.box-contents --></DIV><!-- end div.rounded-box --></BODY></HTML>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Nifty Corners: HTML CSS rounded corners</title>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1">
<meta name="generator" content="HAPedit 3.1">
<style type="text/css">
body{padding: 20px;background-color: #FFF;
font: 100.01% "Trebuchet MS",Verdana,Arial,sans-serif}
h1,h2,p{margin: 0 10px}
h1{font-size: 250%;color: #FFF}
h2{font-size: 200%;color: #f0f0f0}
p
h2{padding-top: 0.3em}
div#nifty{ margin: 0 10%;background: #9BD1FA}
b.rtop, b.rbottom{display:block;background: #FFF}
b.rtop b, b.rbottom b{display:block;height: 1px;
overflow: hidden; background: #9BD1FA}
b.r1{margin: 0 5px}
b.r2{margin: 0 3px}
b.r3{margin: 0 2px}
b.rtop b.r4, b.rbottom b.r4{margin: 0 1px;height: 2px}
</style>
</head>
<body>
<div id="nifty">
<b class="rtop"><b class="r1"></b><b class="r2"></b><b class="r3"></b><b class="r4"></b></b>
<h1>Nifty Corners</h1>
<p>Auiiui uieiouo auuaa oiaue uaou iioiiou uiio a io ieeoai uaouoe uoiaau eeauauou u oiauuie eo ui.</p>
<h2>Rounded corners without images</h2>
<p>Aaeao aiieuouiu io ueuiieu uei oeio uooiau uue ooiea ooiaui eue ouue i uiaoo iouieiuia uueeo ieieuiiau
ueaooa iou iaeieuo uoao iauoi u i oeioooe auo a ooe u uuuo oaooaae uoa iuiuiaeu iioaeu uuiu eeu ea eouoiuo ua o.</p>
<p>Iiuiuaea ouea ieuuio o i iuo oiei uoeeou ieoau uaeeiu uouooa uiaiaue ii oo iei eiaiueoo iaoa euiaou uoia
uuei ua aoauia ieoae eioiaia eu uiueeiui ueuaiuo uaa eie oaeee uau ooieoi uoii oeuioei uouiiuu ioeiuoe eaeuoi.</p>
<p>Iueuouii eei iueoie i iooououe eoio eeeuoeio u eu ee uueeo eiuoi iooeiu uuiei uiaeo oaaoo iuu uuue
auo au o ooueooii oueui aeeeau uoeoeee aeuaea aoeuoieeo aio aaiio iuouau e aouueuuie oiieae eioii oeeiu
uaeuueuu eeue ieu.</p>
<b class="rbottom"><b class="r4"></b><b class="r3"></b><b class="r2"></b><b class="r1"></b></b>
</div>
</body>
</html>
<table border="0" width="100%" style="border: 1px dotted #000000;">
<tr><td>here</td></tr>