$arr = array ( 
 array ( 
   'catid' => '4', 
   'catname' => 'www.1sucai.cn', 
   'meta_title' => '编程素材网' 
  )
);
 
echo json_encode($arr);

[{"catid":"4","catname":"www.1sucai.cn","meta_title":null}]

<?php
$data="JSON中文";
$newData=iconv("GB2312″,"UTF-8//IGNORE",$data);
echo $newData;
//ignore的意思是忽略转换时的错误，如果没有ignore参数，所有该字符后面的字符都不会被保存。
//或是("GB2312″,"UTF-8″,$data);
?>

<?php
$testJSON=array('name'=>'中文字符串','value'=>'test');
echo json_encode($testJSON);
?>

{"name":"u4e2du6587u5b57u7b26u4e32″,"value":"test"}

<?php
$testJSON=array('name'=>'中文字符串','value'=>'test');
//echo json_encode($testJSON);
foreach ( $testJSON as $key => $value ) {
$testJSON[$key] = urlencode ( $value );
}
echo urldecode ( json_encode ( $testJSON ) );
?>

{"name":"中文字符串","value":"test"}