The draft constitution, adopted on Sunday by lawmakers in Havana, includes paragraphs that name the concept of private property for the first time and describe foreign investment as important for economic growth.
Under the new document, future presidents would spend no more than 10 years in office, with the "president of the republic" becoming a role separate from the head of the state council. The new constitution would also create the role of prime minister for the first time since 1976.
Cuba's Communist Party remains the sole legal party in the Caribbean island nation.
Cuban residents are due to deliberate the reforms in public forums over the next three months before voting in favour or against them in a referendum.
Marriage will be defined as the voluntary union between two individuals rather than a man and a woman, paving the way for marriage between same-sex partners.
The inclusion of same-sex marriage in the constitutional reform was championed by lawmaker Mariela Castro, daughter of former president Raul Castro.
