  We improved the discless accretion models of Wynn \& King, considering the
effects of the changing aspect due to the white dwarf spin and the variable
feeding intensity caused by the asynchronism, and set up a more general spot
model which is not sensitive to the different forms of these effects and can be
applied for the period analysis of the optical and X-ray light curve. The spot
model can produce the power spectra compatible with the observations, and its
simulations limit the ratio $P_{spin}/P_{orb}<2$ between the powers at the
white dwarf spin and the binary orbital frequencies, which is a strong
criterion for identification of periods. Then we recognize the periods for CD
Ind, BY Cam and 1RXS J083842.1-282723. The spot model reveals a complex
accretion geometry in the asynchronous polars, which may indicate that the
complex magnetic field causes their asynchronism. We think 1RXS
J083842.1-282723 is a pre-polars because of its highest asynchronism and stable
light curve. Giving the unstable accretion process in asynchronous polars, the
period analysis of the long-term light curve will make the orbital signal
prominent.
