Qualification for election to the office of president
It is incumbent upon the President not to hold any office of profit or occupy any position which carries the right to remuneration. The President is also constitutionally restrained to a candidate for election as a Member of Parliament or a Provencal Assembly. On the other hand if a Member of Parliament or a Provencal Assembly is elected as President, he will cease to hold his out in the Parliament or the Provencal Assembly, as the case may be, on the day be enters upon his office, as President.
According to Article 43
1). The President shall not hold any office of profit in the service of Pakistan or occupy any other position carrying the right to remuneration for the rendering of services. 
2).The President  shall not be a candidate for election as a member of Parliament or Provencal Assembly and if a member of Parliament or, a Provencal Assembly is elected as President, his seat in Parliament or as the case may be, the Provencal Assembly Shall become vacant on the day he enters upon his office. 
1). He is Muslim. 
2). He is not less than forty five year of age. 
3). He is qualified to be elected as a member of the National Assembly.
The question whether a person is eligible for election is to be determined by the Chief Election Commission, and when a person has been declared to have been duly elected as President, the validity of the election cannot be called in question by or before any court or other authority in any manners whatsoever.
Term of office of President
According to Article
1). Subject to the constitution, the President shall hold office for a term five year from the day of enters upon his office Provided that the President shall, not withstanding the expiration of his term, continue to hold office until his successor enters upon his office. 
2).Subject to the constitution, a person holding office as President shall be eligible for re-election to that office, but no person shall hold that office for more than two consecutive terms. 
3).The President may, by writing under his hand addressed to the speaker of the National Assembly resign his office.
Explanation – The present constitution envisages that the president shall be elected by the members of parliament, i.e. members of the Provencal Assemblies in a joint sitting, by secret ballot, in accordance with the provision of the second schedule. If there are only two candidates, the candidate who has secured the large number or votes shall be declare by the Election Commissioner to be elected. If there are three or more candidates and one of them has secured a larger number of votes than the aggregate numbers of votes secured by the rest of the candidates, he shall be declare to be elected. If there are three or more candidates and no candidate has secured the number of votes specified above, a fresh poll shall be hold.
Article 41– The President is elected under article 41 of the constitution through an elected college, consisting of members of the two Houses of Parliament and four Provencal Assemblies.
Provision of Article 41(7) is intended to serve a particular situation relating to a particularized President term of office of the President having been provided for by Article 44 as five years from the date he enters upon his office, would equally apply to the President elected one the occurrence of vacancy or otherwise as no distinction in this behalf is made in any provision governing the subject and Article 41(7) does not detract from the validity of this view.
Power of President
The President in the present constitution is constitutional head of the state. The executive authority of the federation is to be exercised in his name. The President has been given wide power by the constitution. The most important power which has been given to the President in the constitution is the power of proclamation of emergency. The President is satisfied that security of the country or any part of it is threatened by war or external aggression or by internal disturbance may issue a proclamation of emergency is in force, the President may, by order, declare that the right to move any court for the enforcement of fundamental rights shall remain suspended. He can also assure himself, or direct the governor of the province to assume on his behalf the control of all or any of the functions of the government of a Provision of the Province cannot be carried on in accordance with the provision of the constitution.