The Newtonian gravitational constant is regarded as the most fundamental constant. So far, more than 200 experiments have been done to measure its true value. But large discrepancies in those results appeared. Owing to the weakness of the gravitational interaction and the impossibility of shielding its effects, it is very difficult to find new method to measure G. Thus, most previous experiments were based on the torsion pendulum or torsion balance. Here we report the inclining-pull projection method to measure the gravitational constant G. The experimental idea is completely different from previous. With different center distances of two balls, we do this experiment two times and gain two values: , with an uncertainty of about 2.5%; ，with the uncertainty of about 2.3%. It implies it is possible for G not to be a constant.

Keywords: gravitational constant G, torsion balance, precision, displacement