"Listbox"... do you mean an HTML <select>, with <option>s inside ?

Is there some syntax difference and I use only simple HTML within XSLT file?

you do put plain HTML right into your XSLT.

consider this sample

<select>
<xsl:for-each select="/item">
<option><xsl:value-of select="@name"/></option>
</xsl:for-each>
</select>

thank you.

How to add items in this option block?

Like www.google.com and www.mastercard.com in correct way?

see the description of <option> [w3schools.com] at W3Schools

I usually state the value of an option explicitly, like this:

<option value="12345">Ford Prefect</option>

in XSLT, this would turn into:

<select> 
<xsl:for-each select="/item"> 
<option>
 <xsl:attribute name="value"><xsl:value-of select="@value"/></xsl:attribute>
 <xsl:value-of select="@name"/>
</option> 
</xsl:for-each> 
</select>

So, you mean in XSLT:

<select>
<xsl:for-each select="/item">
<option value="12345">Ford Prefect</option>
<option value="12345">Mercedes best</option>
<option value="12345">Fiat Perfect</option>
<xsl:attribute name="value"><xsl:value-of select="@value"/></xsl:attribute>
<xsl:value-of select="@name"/>
</option>
</xsl:for-each>
</select>

I have predefined values of items from server.

10 try it and see if it produces the results you desire.
20 If it doesn't, GOTO 10

debugging is an iterative process. The best way to learn the syntax of a language, whether it's HTML or XSLT, is to read, experiment, and play with it. I'd suggest getting an XSLT debugger which lets you edit XSLT and see the results immediately - there are several good ones out there with trial versions you can play with before purchasing.