Based on the computer and the general scanner, adopting the technology of picture disposure of computer, the Auto GPR1.0 system is developed to increase the measuring precision of the area of leaves. This system can pick up the noting curves according to the differences between the colore of auto-writing paper background and that of noting curves of temperature or humidity, then the computer can obtain continuous data from the values of temperature and humidity noted in auto-writing paper. In system calculation, the absolute error of temperature is less than 0.2℃, and that of humidity is less than 0.2%.