A sample of 46 deep, low mass ratio (DLMR) overcontact binaries (i.e., and ) is statistically analyzed in this paper. It is found that five relations possibly exist among some physical parameters. The primary components are little-evolved main sequence stars that lie between the zero-age main sequence line and the terminal-age main sequence (TAMS) line. Meanwhile, the secondary components may be evolved stars above the TAMS line. The super-luminosities and large radii may result from energy transfer, which causes their volumes to expand. The equations of M–L and M–R for the components are also determined. The relation of P–Mtotal implies that mass may escape from the central system when the orbital period decreases. The minimum mass ratio may preliminarily be from the relations of q–f and q–Jspin/Jorb. With mass and angular momentum loss, the orbital period decreases, which finally causes this kind of DLMR overcontact binary to merge into a rapid-rotating single star.
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