ITA is not so Powerful in China So Here is a great tool in CHINA
Business Class One Way
Flight selected MU5257
Ctrip In Chinese(My Phone):1610CNY
Ctrip In English(My Mac):1705CNY
China Southern official website:They Only sells Economy in this flight
China Eastern official website:1610CNY(Public)/1560CNY(Members Of CE Club) (CE's IT sucks and it crash a few time)
Notice:Found on English Ctrip ,Then go on the official airline website to buy!