The spatial distribution , galactic model parameters and luminosity function of cataclysmic variables ( CVs ) in the solar neighbourhood have been determined from a carefully established sample of 459 CVs .
The sample contains all of the CVs with distances computed from the Period-Luminosity-Colours ( PLCs ) relation of CVs which has been recently derived and calibrated with 2MASS photometric data .
It has been found that an exponential function fits best to the observational z -distributions of all of the CVs in the sample , non-magnetic CVs and dwarf novae , while the sech ^ { 2 } function is more appropriate for nova-like stars and polars .
The vertical scaleheight of CVs is 158 \pm 14 pc for the 2MASS J -band limiting apparent magnitude of 15.8 .
On the other hand , the vertical scaleheights are 128 \pm 20 and 160 \pm 5 pc for dwarf novae and nova-like stars , respectively .
The local space density of CVs is found to be \sim 3 \times 10 ^ { -5 } pc ^ { -3 } which is in agreement with the lower limit of the theoretical predictions .
The luminosity function of CVs shows an increasing trend toward higher space densities at low luminosities , implying that the number of short-period systems should be high .
The discrepancies between the theoretical and observational population studies of CVs will almost disappear if for the z -dependence of the space density the sech ^ { 2 } density function is used .

PACS : 97.80.Gm ; 97.10Yp ; 97.10.Xq ; 98.35.Pr