He suggests five bases for clasification of states in terms of their constitutions:

i. The nature of the State to which the Constitution applies - C F Strong makes a classification between Unitary and Federal States. Eg. The UK is a Unitary States while USA is a federal state. 

ii. The nature of the Constitution - The distinction can be made between states with written or unwritten Constitutions. Eg Written - India Unwritten - Britain.

iii. The nature of Legislature - On the basis of the nature of Legislature, a distinction can be made between Bicameral and Unicameral. Eg. Bicameral - India Unicameral - China.

iv. Executive - It is divided into a Parliamentary and Presidential executive. Eg. Parliamentary- India Presidential - USA