Spectrum compatible artificial earthquake through the modification of available records is widely accepted nowadays.There are four methods for the modification

including scaling method

modifying the Fourier amplitude

modification based on wavelet transform

modification through the adding of wavelet functions.In this paper

the theory and the difficulty in fulfillment are discussed in detail. Through the examples

the advantages and disadvantages of the four methods are discussed.When the discrepancy between the code response spectrum and response spectrum of the available record is large

the scaling method is adopted firstly

then one of the other three methods is utilized for the modification.The last three methods can all retain the temporal variations of the original accelerogram to a certain extent.But the method of adding wavelet is the best in precision.Moreover

the corresponding velocity and displacement time history can be obtained without baseline correction.The method of adding wavelet is recommended in practical use.