Advantages:
Self-pollination helps to maintain parental characters or purity of the species.
The plant does not need to depend on the pollinating agents.
No need of producing a large number of pollen grains.
Flowers do not need to develop devices for attracting insect pollinators.
It ensures seed production. Rather it is used as a fail-safe device for cross-pollinated flowers.
It eliminates some bad recessive characters.
Disadvantages:
Self-pollination does not allow new adaptions according to the change in the environments.
It can lead to the reduced health of the species, due to the breeding of related specimens.
Immunity to diseases decreases.