Kl3 decay is treated using once-subtracted dispersion relations, current algebra, and partial conservation of axial-vector current. The dispersion integrals are evaluated by saturating them with the vector K* and and scalar κ intermediate states. The subtraction point is chosen so that the subtraction constants may correspond to the soft-pion result. It is shown that if f+(t) obeys once-subtracted dispersion relations and f-(t) an unsubtracted one (scheme I), and if fKfπ~=1.16-1.28, then f+(0) cannot be close to 1 unless a κ meson exists. In this case it is also shown that both λ+ and λ- are small, while ξ=f-(0)f+(0) is small and negative. We also consider the possibility of having once-subtracted dispersion relations for both f+(t) and f-(t) (scheme II). It is found that the results of schemes I and II are the same if either (a) there exists a κ meson with mass around 1 BeV and f+(0)~=1, or (b) no κ meson exists, but f+(0)~=fKfπ. If, on the other hand, no κ meson exists, and if f+(0)~=1, while fKfπ~=1.28, then one is able to get λ- an order of magnitude bigger than λ+ in scheme II. Thus there is a possibility for large λ- only in scheme II. Furthermore, in scheme I, using partial conservation of vector current for the strangeness-changing vector current, we obtain (fKfπ)f+- 1(0)~=mκ2(mκ2-mK2). For (fKfπ)f+-1(0)~=1.28, we predict mκ~=1.06 BeV.