If it's a dynamic form, you can set a default value in struts-config.xml:

<form-bean      name="contactForm" 
                  type="edu.example.ContactForm"> 
      <form-property name="onHoldFlag" 
                               type="java.lang.Boolean" initial="true"/> 
  </form-bean> 

I used html:checkbox in jsp and set value="true" to
precheck it.
and it works corretly , i suggest you try agin .

simply way you could use :

<html:checkbox property="true" />
if you wanna preChecked on load a web page  Or you could set it with parameters that you pass it.
<html:checkbox property="<%= checked %>" />

In the formbean(ActionForm) you have to define a boolean member variable and in the reset() method set it to true or false for checked and unchecked respectively.

u could set u'r checkBox value in the FormBean when
initilazie it!

You must define check value in value attribute  and set init property in your form bean with this value. For example write as following:

In source code:
...
YOUR_FORM_BEAN,setStatus("y");
...

In jsp page:
...
<html:checkbox property="status" value="y"/>
...