Here are the ones, that I know of...
(and without the joint ventures such as Yantai Perzina, Beijing Heintzman, Pearl River/Yamaha, and Xinghai/Kawai)

Guangzhou Pearl River (www.pearlriverpiano.com)

Beijing Xinghai (www.xinghai-piano.com)

Dongbei (www.dongbeipiano.com)

Shanghai Yue Yin Piano (www.marshalpiano.com or www.shyypiano.com)

Shanghai Piano Co. (Strauss) (www.strausspiano.com)

Shanghai Ying Man Piano Co. (www.ykum.com)

Shanghai Artfield Piano Co. (www.artfieldpiano.com.cn)

Yantai Longfeng Pianoforte (www.longfengpiano.com)

Hangzou Goodway Piano Co. (www.goodwaypiano.com)

China Fujian Aiyue Piano Co. (www.fjscay.com)

Nanjing Moutrie Piano Co. (www.moutrie.cn)

Qingdao Sejung (www.ascpianos.com)

Dalian Atlas Instrument Co. (www.atlas.com.cn)

Please feel free to correct and/or contribute to the list.. \:\)