Abstract: This paper presents a new method named Acoustical Holography which can be used to identify noise sources. A new formula of holography reconstruction is obtained, based on the Kirchhoff integral formula. Some simulating tests carried out using the new formula. Comparison with other reconstruction formulas proved the new formula effective. Using Acoustical Holography, some interesting results are shown about the noise of a vehicle. The results proved Acoustical Holography is an effective method for complex noise.