the π mesons. By using the parameterized form for the parton distribution function of the meson

obtained from the statistical model and combining the meson induced Drell-Yan data，the u quark

distribution function of the K meson is extracted， the values of the parameters are

determined. The extraction shows that the statistical approach can describe the ratio of the

K-nucleon Drell-Yan and π-nucleon fairly well. It is also found that the chemical potential of

the u quark with positive helicity inside the K meson is larger than that inside the π meson.