Many factors contributed to the fall or decline of Jukun kingdom.
First, the kingdom had a series of wars with her neighboring towns. Again, the kingdom lacked organizational structure (i.e. it was a decentralized state) and as a result had many autonomous chiefs.
Moreover, their counter wars led to the negligence of agriculture in the area and as a result, famine captured the kingdom very well.
Again, in the 17th century, the leaders of the empire laid much emphasis on rituals and ceremonies other than military effort.
The abolition of the slave trade to be replaced by trade in palm oil, palm kernel and other raw material was another factor.
Finally, the Fulani jihad of Usman Dan Fodio conquered the kingdom.