China's nonfinancial outbound direct investment (ODI) fell by 45.8 percent year-on-year in the first half of 2017, according to data released by the Ministry of Commerce on July 13.

The drop was a result of an optimized structure of outbound investment and the country's efforts to curb irrational deals, according to Gao Feng, the ministry's spokesperson.

China became a net capital exporter for the first time in 2015 with its ODI exceeding capital inflows. The country became the world's largest participant in international mergers and acquisitions in 2016. Its non-financial ODI in 2016 soared 44.1 percent year-on-year to US$170 billion.

Chinese enterprises have fastened the pace of overseas investment, but experts have cautioned that they should avoid blind investment and increase efficiency.

Some Chinese firms failed to make an objective evaluation on the business environment and investment prospects of the host countries, which leads to economic losses, said Mei Yuxin, a researcher at the Chinese Academy of International Trade and Economic Cooperation under the Ministry of Commerce.

China has tightened its supervision on unwise investment and is expected to introduce its first regulation on ODI this year. The Ministry of Commerce and National Development and Reform Commission are leading the formulation work, which will help prevent unwise and illegal overseas investment through stricter measures.