The bridge across the Surkhob river in central Tajikistan will be 920 meters (3,018 ft) long and constructed mostly by Tajik workers, according to officials.
China's Asian Infrastructure Investment Bank (AIIB) will lend Tajikistan the money needed for construction of the bridge, a spokesperson for the Tajik transport ministry told AFP on Wednesday.
Moscow remains Tajikistan's biggest trading partner, but over the last decade, China has invested more than $4 billion in its landlocked neighbor, rivaling the Kremlin's influence.
The bridge project will cost around $60 million, the Tajik ministry earlier announced.
It will be built in a mountainous area with treacherous roads near a vast unfinished Soviet hydroelectric dam that Tajikistan plans to complete.
China shares a roughly 500-kilometer (311-mile) border with Tajikistan and has been investing heavily in transport infrastructure in its Central Asian neighbors as it seeks to improve road links used to deliver goods to Europe.
There is not yet a start date for the project, the spokesperson said, adding that 80% of the workers on the project would be Tajik and the remaining 20% Chinese specialists.
Tajikistan is one of the poorest of the former Soviet republics with a GDP of under $15 billion, a third of which comes from remittances from migrant workers, most of whom work in Russia.
Beijing holds around a third of Tajikistan's foreign debt of close to $1 billion.