A Chip-On-Lead (COL) type semiconductor package having small chip hidden between leads is revealed. The lower surfaces of the leadframe's leads are attached to a wiring substrate and the leads are horizontally bent to form a die-holding cavity. A smaller chip is disposed on the wiring substrate by passing through the die-holding cavity to be on the same disposing level with the leads. At least a larger chip is disposed on the leads to overlap the smaller chip so that the small chip does not extrude from the leads. The encapsulant encapsulates a plurality of internal parts of the leads, the wiring substrate, and the larger chip. Therefore, the conventional unbalance issue of mold flow above and below the leads leading to cause excessive warpage can be avoided and numbers of stacked larger chips can be increased to have larger memory capacities.