It depends on the snake. If the "stripes" are bands around the snake and you live in India, Bangledesh, or Southeast Asia, yes it is poisonous if it is the Banded Krait.
The Telescopus semiannulatus, also called Tiger snake of Africa has venom but is not dangerous to humans. It is also banded.
If the snake has stripes that go head to tail, it may be the garter or ribbon snake. They are found in North America. They are harmless and are frequently kept as pets.
It is best for you to go to do a search on the description of the snake.