There arc some strong velocity discontinuities or transitions in the earth’s curs! and upper man tie

which can be reconginzed by tracing converted-wavc phases in seismic wave records. However

when seismic stations are set in sedimentary area

the recorded converted-wave information will be masked by the recorded multiple reflected-waves caused by sedimentary formations. In this case

it is hard to identify the velocity discontinuity from receiver function. Now there are not many effective methods to separate the mixed seismic converted wave and multiple reflected-waves. In this paper

a new methods is proposed based on Independent Component Analysis （ICA） to implement the separation of seismic converted-wave and multiple reflected-waves recorded in sedimentary basin.ICA is a novel statisticsal method

which was developed recently for data analysis and signal process ing. The purpose is to find a representation of Non-Gaussian multivariate date

so that each components of the vector are statistically independent

or as independent as possible. In many applications

the aim transformation is to capture the basic structrue in data

including features abstraction and signals separation. Independent Component Analysis usually represents data by linear transformation. Based on higher-order statistics

ICA is not only de-correlation but independent compared with Principal Component Analysis

factor analysis and projection pursuit

which are based on de-correlation. In sedimentary basin

large seismic converted-wave and multiple reflected-waves are mixed

which conforms to the basic ICA Model under some conditions. ICA can be used to separate them. In this paper

we first summarize the principal theory and some fast algorithms

at the same time

numerically implement the fast ICA （FastICA for short） and its updated version by the author. On the base of analyzing the features of seismic signals

we do preliminary studies and try to apply ICA in seismic signals separation. We suppose that the seismic records of each station set in the sedimentary area are some linear mixture of seismic converted-wave and multiple re-flected-waves. The experimental data were acquired in a sedimentary basin of Shandong Province. There were 18 receiver functions obtained from corresponding seismic records. The separation was executed in time and frequency domain respectively and the FastICA algorithm was adopted. Our work shows a good prospect of ICA application in seismic signals separation of transformed-wave and multiples. On the separated convcrted-wave records

the seismic phases can be traced easily and more accurate interpretation of velocity discontinuities can be obtained. The specific operation is : in time domain

we included two close stations’ records in one group and used FastICA to separate two signals from them

supposing that separated signals were converted-wave and multiple reflected wave respectively; in frequency domain

we first transformed the two receiver functions into frequency Domain

then applied FastICA to real part and imaginary part respectively

thirdly

combined the ICA results according to the real and imaginary part

finally inversed them from frequency domain to time domain. So we separate the converted and reflected signals. Some details of the separated signals were presented in the paper.In conclusion

the paper proposed a separation method of seismic converted wave and multiple reflected waves in sedimentary area. Moreover

the paper presented a preliminary interpretation of velocity discontinuities in the earth. The reserach results show that the ICA method to separate converted and reflected wave is feasible. For the problem dealt in the paper

the effects processed in time or freqency domain arc similar. The ICA based Method extended the use of receiver function technique.Due to the ambiguity of basic ICA

the separated signal is of sign undetermined. So the Extended ICA should be studied and applied in the subject of the paper to overcome the problem

thus better effects will be obtained.