emacs fontset no window

[davemilter]

I have such code in ~/.emacs:

(if (eq window-system 'x)
  (set-fontset-font (frame-parameter nil 'font)
  'han '("Vera Sans YuanTi" . "unicode-bmp"))
)

I suppose that set-fontset-font should not be executed in
"emacs -nw", but exatcly that lines:
  (set-fontset-font (frame-parameter nil 'font)
  'han '("Vera Sans YuanTi" . "unicode-bmp"))

 cause problem during startup in "emacs -nw" mode,

so I completly not understand logic of emacs,
can anybody explain?