BEIJING—China is losing its competitive edge as a low-cost manufacturing base, new data suggest, with makers of everything from handbags to shirts to basic electronic components relocating to cheaper locales like Southeast Asia.

The shift—illustrated in weakened foreign investment in China—has pluses and minuses for an economy key to global growth. Beijing wants to shift to higher-value production and to see incomes rise.

But a de-emphasis on manufacturing puts pressure on leaders to make sure jobs are created in other sectors to keep the world’s No. 2 economy humming.

Total foreign direct investment flowing into China fell 3.7% in 2012.

-Wall Street Journal Asia