Gravitational Field

The earth pulls down on every kilogram with a force of 10 Newtons. We say that the Earth's gravitational field strength (at ground level) is 10 Newton per kilogram (10N/kg). In other words, an object with a mass of 1 kg has a weight of 10N. That is why an object's weight varies from place to place but its mass remains the same wherever it is. An example is the gravity on the moon is 1/6 of it on earth. Thus one man who weights 60kg(600N) on weighs 10kg(100N) on the moon.
But his mass remain at 60kg.