Dissolution of rent, as one of the most important factor, has causes and consequences are: Annulment of rent may divided ino two. First, from the beginning of a contract such as: the rent of unknown and uncertain object, left unsaid of the period, the impossibility of desired benefit and the rent in life time of one of the parties. Second, the annulment of rent in the middle of contract for the waste of rented premises. Basically, the effect of annulment returns to the past. If the rented object changes in the middle of the contract, its effect is comminuted to the future.

The cancellation of rent; that options are the most causative of reason relate to it, and option of defect, condition and unfulfilled condition are the most important of them, effect of cancellation comminuted to the future.

With attention to temporality of rental contract, termination of period is other factor. Because, period base is criterion of benefits, that benefit independent on factor of time. All of its feature is studied exactly.

Except general effect of annulment and cancellation, there is other effects likeness rental value, be trustee of tenant after termination of time and eviction.

Causes and effects of dissolution of rent are studied comparatively with Imamiye Jurisprudence and Egypt Law.