  The modified Gottfried sum rule makes clear importance of the high energy
region not only in the theoretical meaning but also in the numerical analysis.
In this talk, it is shown that the soft pion theorem in the inclusive reaction
at high energy can explain the magnitude about $0.02 \sim 0.04$ in the NMC
deficit. The main contribution comes from the small $x$ region. We also
estimate the soft pion contribution to the Ellis-Jaffe sum rule and show it to
be negligible. However we find that the contribution to $g_1^{ep}$ becomes
positive below $x = 0.002$.
