Through researching profit-making mode and income structure of the retailers, the paper states that it is not the power of channel, but the suppliers' contribution to the amount of gross profit and return-profit decides the portion of slotting allowance. To some extent, the slotting allowance can exchange the other incomes for the retailers. The collection of slotting allowance has some rationality. Moreover, the government can not restrict the collection of slotting allowance directly.