RevisedV/V max test with incompleteness-compensated factors and its application to X-ray quasar sample

Both density- and luminosity-evolution of quasars proceed sumultaneously. If only one of them is considered, the value of V/V _max would be too high. Here we present an idea that the quasar luminosity-redshift relationship curve can be obtained by statistics, from which the incompleteness-compensated factorK(Z|l _min) for each source will be given, and then theV/V _max test for density law can be carried out. We use this revisedV/V _max test in investigating 3CR and 4C samples including the 3CR sources detected in X-ray. The result is that the space density distribution of quasars is relative toq _o.