The plans to build the new passenger lines came after China's recent move to spend $113 billion to build railways and five airports.
The infrastructure projects should foster investment, the biggest driver in the world's second-largest economy, which has sagged this year as a cooling manufacturing sector and a softening housing market discouraged spending.
The new railway lines would run in the southern province of Guangdong, southwestern provinces of Guangxi and Sichuan, Inner Mongolia and the western province of Gansu, the National Development and Reform Commission said in a statement on its website.
Official data last week showed that China's economy lost further momentum in October, with factory growth dipping and investment growth hitting a near 13-year low.