To estimate the number of mechanical vibration sources from the convolu tive mixtures with fewer sensors than sources, a new method composed of EMDSVD BIC(Empirical Mode Decomposition, EMD; Singular Value Decomposition, SVD; Bayesi an Information Criterion, BIC) is proposed. The characteristic of vibration so ur ces, which is intrinsic mode function(IMF) is obtained through the EMD of them ixtures. The complex matrix of the IMF of different mixtures is used to get the eigenvalue of sources by using SVD. The eigenvalue is employed to det er mine the number of sources by means of BIC. It is verified that the new method y ields a correct estimate of source number in the simulation test and experiment. This work is help to analyze the mechanical vibrations in the fault monitoring system and to separate the useful mechanical vibration signals efficiently from the mixtures.