You could use blockscript, the free version will still redirect any country specified even after the trial period expires, there is a worpress plugin version I've used myself in the past, don't know how or if it'll impact site performance though.
Or you could try the 'proxy' method using maxmind geoip, I've just tried this on a wordpress site and it seems to work for me, but try at your own risk and make backup copies of any files changed of course
First upload the maxmind files, GeoIP.dat + geoip.inc (zip file attached or download both from maxmind.com) into your domain root folder.
Then edit your /index.php file in the sites root folder and add this code at the beginning of the file, underneath the the "<?php" part:
It will redirect all Chinese (and anonymous) traffic to baidu.com, though you can change the redirect url to one of your choosing, just edit. You may have to add the code again after any WP updates if they replace the index file, but it is currently installed on thesitecheck.com and that still works. I tried redirecting UK traffic (where I am) and it did the job, so I took that bit out and left the rest. You can also add any other country you need or want to block as well just by editing the file and adding the country name in quotes, seperated by commas.
// THIS IS THE GEOIP COUNTRY BLOCKING CODE
include('geoip.inc'); //this file must exist in your directory
$gi = geoip_open('GeoIP.dat',GEOIP_STANDARD);
// get the ip of the visitor
$addr = getenv('REMOTE_ADDR');
// translate ip to a country
$country = geoip_country_name_by_addr($gi, $addr);
// close the geo database
$badcountry = array("China", "Anonymous Proxy", "Satellite Provider", "Other");
// redirect them if country in above string
header('Location: http://www.baidu.com'); //enter a url or page on your site
// END OF COUNTRY BLOCKING CODE
I can't say if this will impact site performance either tbh, I have no way to measure it, but if you get a lot of Chinese traffic and it stops that then overall site performance may well improve because of it, plus it'll save a heap of bandwidth.
There's a couple of other plugins I use too, one is Bad Behavior which keeps out bad bots, the other is WP-Copyright-Protection which disables any right click copy'n paste efforts.
Edit: Not sure it'll stop specific pages loading, maybe there's a better place to put the code to work on all pages, I did try the template header.php but that didn't work, but then I'm not a wordpress kinda guy, perhaps someone else has a better idea for it.
'Nother edit: Just tried it with different pages and it seems to redirect those as well, so could be an easy solution.