The dependence of proton emission half-lives on the nuclear asymmetry parameter is investigated using the WKB method and two types of empirical formula.Using the single-folding formalism with asymmetry-dependent nuclear radius and surface diffuseness of nuclear matter,the nuclear potential and consequently the half-life are functions of the asymmetry factor.Despite small values of asymmetry in neutron-deficient proton emitters,noticeable changes in the half-lives are observed.The addition of an asymmetry parameter term to the two forms of empirical formulas leads to a reduction in the rms error for ground state and isomeric transitions.A noticeable reduction of about 43% is obtained for isomeric transitions in the second form of the empirical formula.Considering ground state transitions in two categories,odd-even and odd-odd emitters,and adopting deformation and asymmetry-dependent empirical formulas,the rms decreases remarkably.The lowest values of rms errors,viz.0.1492,0.2312,and 0.1999,are obtained for the aforementioned empirical formulas for ground state transitions of odd-even and odd-odd emitters and for all isomeric transitions,respectively.