As is known, South Korea is one of the important investment sources and trade partners to the region of the Korean minority nationality in China. This paper, using Grey Correlation Method, shows that market factor, cost factor and education factor are main factors deciding the investment from South Korea to the region of the Korean minority nationality in China. Fur ther more, the paper researches the trade effect of South Korean investment in the region of the Korean minority nationality in China from five aspects, I. e. total investment, investment scale, investment motivation, investment mode and investment type. We find that South Korean investment affects the trade positively.