Conditional field on checkbox is not woking
Please try this code ... It works !!

$form['field_type'] = array(
  '#type'    =&gt; 'checkbox',
  '#default_value' =&gt; 0,
  '#title'   =&gt; t('Choose entry type.')
);

$form['text'] = array(
  '#type'          =&gt; 'textfield',
  '#title'         =&gt; t('Enter the text'),
  '#states'        =&gt; array(
     'visible'      =&gt; array(
       ':input[name="field_type"]' =&gt; array('checked' =&gt; TRUE),
     ),
   ),
);