A Serbian Defense Ministry statement after a visit by a high-ranking Chinese military delegation thanked Beijing for economic and military support.
Serbian officials said China has agreed the sale of armed drones, marking the first export of Chinese remotely piloted aircraft to a European country.
Defense Minister Aleksandar Vulin said the delivery expected in the coming months "will greatly strengthen the Serbian military, which will gain capabilities it has not had in the past."
Serbia was at war with its neighbors in the 1990s. The country, which is formally seeking European Union membership, has already been boosting its armed forces with Russian warplanes, battle tanks and other equipment.
China has increasingly been economically and politically active in Serbia and elsewhere in southeastern Europe as part of its global Belt and Road campaign. The engagement near or within NATO's turf have triggered Western concerns over rapidly increasing Chinese influence in the region.