This paper addresses the extraction of frequency, amplitude, and phase of sinusoidal components directly from modified discrete cosine transform (MDCT) domain, which is broadly used in many digital audio applications. An efficient method is proposed for portable device based on the approximation of MDCT expression and the simple combinations of local maximum MDCT coefficients. By extracting the frequency and amplitude of a stationary sinusoid, the experimental results demonstrate that the proposed algorithm produces accurate results with low computational complexity.