There maybe life living on other planets. But the chance is small. And we haven't found any life on any other planets till now.
As a planet bearing living things, it must have a proper size for absorbing an atmosphere and a mild climate in which the temperature is between 0Ã¢ÂÂ~100Ã¢ÂÂ so that water can exist in the form of liquid. Besides it must contains the appreciate chemicals which can be transformed into living things. As the requirement is so restrict, there is only tiny chance for us to find a planet like this.
But we will never lose heart. Now that one planet- earth can bear life, why isn't there another planet which can do the same in such an enormous universe? The main problem is that we haven't discovered any planet yet outside the solar system. Namely, we haven't found any other system similar to the solar system which consists of one star and several planets. So many scientists can't help thinking that it's earth and the star system an odd, an exception in the universe. Maybe civilization itself is an odd. And we exist simply because of an accident at the edge of the milky way.
Thinking of that is too frustrated. And no scientist would be willing to accept it as true. So we shall just keep our hopes and continue to explore the space till one day when miracles appear.