Abstract: The methods of two kinds for calculating the capacitance and electric field between an unparallelplate capacitor are presented： the one is by using the concept of parallel plate capacitor and the formula of capacitors connected in parallel, another is by using the electric energy formulae of an electric field and a capacitor with charges. It is found in comparison with the two methods that the second method is stricter, simpler, clearer and more innovative.

Key words: unparallel-plate capacitor, electric field intensity, capacitance, electric energy