June FDI totaled $12 billion, ministry spokesman Shen Danyang said. Declining investment in China's property sector also was blamed, China's Global Times reported.
FDI in the first six months of 2012 totaled $59.1 billion, down 3 percent from the same period of last year.
The newspaper quoted the U.N. Conference on Trade and Development as saying global FDI is expected to increase at a slower rate to $1.6 trillion this year due to slow global economic growth.
China's GDP growth in the second quarter fell to 7.6 percent year-on-year, the sixth consecutive quarter of a slowdown and the slowest pace in more than three years.
"China's economy will hopefully pick up in the second half of the year, which will boost investor confidence," Shen said.