This is a Japanese Imari porcelain plate manufactured by the Arita kiln complex on the island of Kyushu.
If you upload close-ups of the colour decorations, I may be able to tell you which period it is from.
Nov 13, 2011
plate by: peter
This plate has a Japanese decoration, and what appears to be a Chinese Chenghua mark. Ming dynasty marks like this were frequently used for decoration purposes on Japanese wares. Not a Chinese plate.