  We present the evidences for the existence of a universal scaling behavior of
the production of $\pi^0$ at all transverse momenta in heavy-ion collisions at
all centralities and all collision energies. The corresponding scaling behavior
of the quarks is then derived just before the quarks recombine with antiquarks
to form the pions. The degradation effect of the dense medium on the quark
$p_T$ is derived from the scaling distribution. In the recombination model it
is then possible to calculate the $p_T$ distributions of the produced proton
and kaon, which are scaling also. Experimentally verifiable predictions are
made. Implications of the existence of the scaling behavior are discussed.
