The focus of spending is on building a China-Pakistan Economic Corridor (CPEC) - a network of roads, railway and pipelines between the long-time allies.
They will run some 3,000km (1,800 miles) from Gwadar in Pakistan to China's western Xinjiang region.
The projects will give China direct access to the Indian Ocean and beyond. China says it will invest some $46bn in Pakistan, providing Beijing with access to the Arabian Sea to increase its trade with Europe, the Middle East and Africa.
This marks a major advance in China's plans to boost its influence in Central and South Asia, correspondents say, and far exceeds US spending in Pakistan.
