The International Space Station, also knows as ISS, is not completed yet but at the moment its dimensions are:

Length: 51 m. (167 ft.)
Width: 109 m. (357.5 ft.)
Height: 20 m. (66 ft.)
Mass: Aprox. 450.000 kg. (990.000lb.)

The Space Station is an artificial, habitable satellite in space launched in 1998.
It is a collaborative project of the space agencies from the USA, Russia, Europpe, Japan and Canada.
The ISS will used to study the effects of Zero gravity in plants, animals and humans.