Qianlong Nian Zhi mark -

Chinese Emperor Hongli (Qianlong) reign period was 1736-1795. Mark of his reign is still in use by porcelain makers. On later pieces is usually used four characters mark, which ommits Da Qing dynasty name.

This mark is probably from 1950s. Qianlong Nian Zhi mark was often used in 1960s and 1970s on pieces decorated in Hongkong.