Abstract: This paper presents a new method of two-dimensional direction of arrival (DOA) estimation for low altitude targets, which is based on intensity measurement using a three-dimensional acoustic vector-sensor. With the perfect characteristics of acoustic vector sensor in the low frequency band, accurate DOA estimation is achieved with small array size. The validity of the proposed method is assessed by numerical simulations on the noise signals generated by a helicopter. The influence of acoustic sensor size, integral time and signal to noise ratio to the accuracy of DOA estimation is investigated, respectively. The performance comparisons demonstrate that the new method outperforms the traditional time-delay measurement based one for a small acoustic array.