How many astronauts have walked on the moon?

Till now twelve but Amstrong was the first.

So far 12 astronauts and many are expected in the future.

There have been several of them.

As per my internet research, total 12 Astronauts landed on the moon.

Totally of 12 Astronauts walked on the moon.

You can go through this link.

http://en.wikipedia.org/wiki/List_of_Apollo_astronauts

Twelve astronauts walked on the moon between 1969 and 1972. They were part of the six Apollo missions which each landed two astronauts on the moon's surface.
http://coolcosmos.ipac.caltech.edu/cosmic_kids/AskKids/moonastronauts.shtml

As per my research and my knowledge, there are about 12 astronauts who walked on the surface of moon.