Please provide a test case - e.g. a minimal stylesheet demonstrating the
problem.  Also please state what operating system and library is being used.

Bill

<?xml version="1.0" encoding="Shift_JIS"?>

<xsl:stylesheet version="1.0"
      xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
      xmlns:jpopc="http://www.jpo.go.jp" >
<xsl:output method="html" encoding="UTF-16"/>
*******************Abbreviation on the way***************
<!-- ==========================================================
     jpopc:size
     ===========================================================-->
<xsl:template match="jpopc:size">
  
  <xsl:variable name= "size_kb">
   <xsl:value-of select="ceiling(. div 1024)" />
  </xsl:variable>

  <xsl:choose>
    <xsl:when test="(. ='')or(round(.) ='0')">
      <xsl:value-of select="'00000'"/>
    </xsl:when>        
    <xsl:when test="string-length($size_kb) &lt; 6">
      <xsl:call-template name="零埋め">
        <xsl:with-param name="i" select="6 - string-length($size_kb)" />
        <xsl:with-param name="count" select="1" />
      </xsl:call-template>
      <xsl:value-of select="$size_kb"/>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="'-----'"/>
    </xsl:otherwise>
  </xsl:choose>
  
</xsl:template>
******************************************************************
My xml follows:
<?xml version="1.0" encoding="Shift_JIS"?>
<!DOCTYPE jpopc:procedure SYSTEM "v4crc00.dtd">
<jpopc:procedure xmlns:jpopc="http://www.jpo.go.jp">
  <jpopc:document-type jpopc:unconfirmed-state="0">012010</jpopc:document-type>
  <jpopc:computer-name>FURUMI2-PC</jpopc:computer-name>
  <jpopc:user-name>t-furumi</jpopc:user-name>
  <jpopc:distinction-number></jpopc:distinction-number>
  <jpopc:relation-file>
    <jpopc:application-receipt-list></jpopc:application-receipt-list>
  </jpopc:relation-file>
  <jpopc:procedure-infomation>
    <jpopc:result>
      <jpopc:software-message>正常</jpopc:software-message>
      <jpopc:communication-result></jpopc:communication-result>
      <jpopc:fd-and-cdr></jpopc:fd-and-cdr>
    </jpopc:result>
    <jpopc:law>1</jpopc:law>
    <jpopc:document-name jpopc:document-code="A1523">手続補正書</jpopc:document-
name>
    <jpopc:file-reference-id>A-63-1-A</jpopc:file-reference-id>
    <jpopc:invention-title></jpopc:invention-title>
    <jpopc:application-reference>
      <jpopc:registration-number></jpopc:registration-number>
      <jpopc:application-number>2000123456</jpopc:application-number>
      <jpopc:application-date>19990110</jpopc:application-date>
      <jpopc:international-application-number></jpopc:international-application-
number>
      <jpopc:international-application-date></jpopc:international-application-
date>
      <jpopc:reference-id>G2000-0001</jpopc:reference-id>
      <jpopc:appeal-reference-number>200012345</jpopc:appeal-reference-number>
      <jpopc:appeal-reference-date>20000104</jpopc:appeal-reference-date>
      <jpopc:number-of-annexation></jpopc:number-of-annexation>
    </jpopc:application-reference>
    <jpopc:submission-date>
      <jpopc:date>20030701</jpopc:date>
      <jpopc:time></jpopc:time>
    </jpopc:submission-date>
    <jpopc:page></jpopc:page>
    <jpopc:image-total>70</jpopc:image-total>
    <jpopc:size>174733</jpopc:size>
    <jpopc:receipt-number></jpopc:receipt-number>
    <jpopc:wad-message-digest-compare></jpopc:wad-message-digest-compare>
**************************************************************
DTD:
	<!ELEMENT jpopc:size						( 
#PCDATA )			>

Sorry, but what you have provided is not sufficient.  The stylesheet is not
complete and cannot be used in it's current state; the xml file is also not
complete, and also (because of the special characters) would have to be included
as an attachment (rather than just text).

I suspect that your trouble is really not a problem with 'ceiling', but rather a
problem with your <xsl:call-template name="零埋め"> (which was not included). 
The reason I suspect that is because the following minimal stylesheet:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
      xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:template match="size">
  <xsl:variable name= "size_kb">
   <xsl:value-of select="ceiling(. div 1024)" />
  </xsl:variable>

  <xsl:value-of select="$size_kb"/>
</xsl:template>
</xsl:stylesheet>

when processed against a corresponding minimal test file:

<root>
 <size>1234</size>
 <size>174733</size>
</root>

produces the following:
bill@billsuper ~/gnomecvs/work $ xsltproc bug.xsl bug.xml
<?xml version="1.0"?>

 2
 171

which is exactly what is expected.  If you still believe there is a problem
within the library, please provide a complete test case which demonstrates it.

Bill

I found bug of xsl.
Thanks for your advice.