As far as I know, there are two:
1) Kiangsu & Chekiang (local stream) - From Nursery up to high school
It's like 90% Mandarin, with one class in English.
2) Tutor Time International Nursery & Kindergarten (from Toddler Activity Group -6 months up, to K3)
Each session is split equally into 50% Mandarin and 50% English.
<They have a banner ad on this site, so you can click on it to find out more... or you can PM me. I'd be happy to answer questions. My son is in K2 there now.>