1 the society was divided into three estates,namely
1 first estate- nobles and church officials who enjoyed all privileges
2 second estate-the traders doctors teacher etc , all people belonging to middle class.they were denied respect and treated badly.
3 third estate-it constituted the peasents,who lead a very miserable life
so.these discrimination and growing power of middle class i.e,they became wealthy was one reason for french revolution.

2 monarchy-the king louis and her wife marie antonete squandered all the money.they used the money for their enjoyment and other desires rather than using it for welfare of the people.they were very harsh in the treatment of their people
France in 1789 was one of the richest and most powerful nations in Europe. Only in Great Britain and the Netherlands did the common people have more freedom and less chance of arbitrary punishment. Nonetheless, a popular rebellion would first to bring the regime of King Louis XVI of France under control of a constitution, then to depose, imprison, try, and execute the king and, later, his wife Marie Antoinette.

Many factors led to the revolution; to some extent the old order succumbed to its own rigidity in the face of a changing world; to some extent, it fell to the ambitions of a rising bourgeoisie, allied with aggrieved peasants and wage-earners and with individuals of all classes who were influenced by the ideas of the Enlightenment. 
As the revolution proceeded and as power devolved from the monarchy to legislative bodies, the conflicting interests of these initially allied groups would become the source of conflict and bloodshed.

Certainly, all of the following must be counted among the causes of the revolution:

Resentment of royal absolutism.
Resentment of the seigneurial system by peasants, wage-earners, and a rising bourgeoisie.
The rise of enlightenment ideals.
An unmanageable national debt, both caused by and exacerbating the burden of a grossly inequitable system of taxation.
Food scarcity in the years immediately before the revolution.

1.Absolutism and privilege 
3.American Influence
4.Food Scarcity