A linkage brick assembly , comprising: at least one first linkage brick comprising a top face , a bottom face and four side faces between said top face and said bottom face , each of said side faces forming a traverse engaging groove extending laterally; at least one second linkage brick comprising a top face , a bottom face and four side faces between said top face and said bottom face , each of two opposite side faces of said side faces forming a traverse engaging protrusion extending laterally, and each of the other two opposite side faces of said side faces forming a vertical engaging protrusion extending vertically; and at least one third linkage brick comprising a top face , a bottom face and four side faces between said top face and said bottom face , each of said side faces forming a vertical engaging groove extending vertically; wherein each of said traverse engaging grooves of said first linkage brick is used to engage with each of said traverse engaging protrusions of said second linkage brick through lateral sliding, and each of said vertical engaging grooves of said third linkage brick is used to engage with each of said vertical engaging protrusions of said second linkage brick through downward sliding; and wherein a top face and an outer side face of each of said vertical engaging protrusions of said second linkage brick define a wedged corner , and each of said vertical engaging grooves of said third linkage brick correspondingly forms a wedged grooved portion , said wedged corner of each of said vertical engaging protrusions being used to engage with said wedged grooved portion of each of said vertical engaging grooves . at least one first linkage brick comprising a top face , a bottom face and four side faces between said top face and said bottom face , each of said side faces forming a traverse engaging groove extending laterally; at least one second linkage brick comprising a top face , a bottom face and four side faces between said top face and said bottom face , each of two opposite side faces of said side faces forming a traverse engaging protrusion extending laterally, and each of the other two opposite side faces of said side faces forming a vertical engaging protrusion extending vertically; and at least one third linkage brick comprising a top face , a bottom face and four side faces between said top face and said bottom face , each of said side faces forming a vertical engaging groove extending vertically; wherein each of said traverse engaging grooves of said first linkage brick is used to engage with each of said traverse engaging protrusions of said second linkage brick through lateral sliding, and each of said vertical engaging grooves of said third linkage brick is used to engage with each of said vertical engaging protrusions of said second linkage brick through downward sliding; and wherein a top face and an outer side face of each of said vertical engaging protrusions of said second linkage brick define a wedged corner , and each of said vertical engaging grooves of said third linkage brick correspondingly forms a wedged grooved portion , said wedged corner of each of said vertical engaging protrusions being used to engage with said wedged grooved portion of each of said vertical engaging grooves . <EOS>