A prosthetic knee joint with buffering and braking effects has an upper connecting base (10), a linking assembly (20), a braking assembly (30), and a lower connecting base (40), which form a four-bar linkage. The upper connecting base (10) has two extending lugs (11) and an accommodating recess (12). The linking assembly (20) has two linking arms (21) respectively and pivotally connected to the upper connecting base (10). The braking assembly (30) has a braking arm (31) protruding into the accommodating recess (12) and pivotally connected to the two extending lugs (11). The lower connecting base (40) is connected to the linking assembly (20) and the braking assembly (30). A cushion (43) provides a buffering effect during walking. Thus, the prosthetic knee joint has simplified structure and reduced cost and is convenient in assembly and use.一種具有緩衝及卡制效果的義肢膝關節，其設有一上連接座、一連動組件、一制動組件及一下連接座，該上連接座設有兩延伸耳部及一容設槽，該連動組件設有兩與上連接座相樞接的連動臂，該制動組件設有一伸入容設槽中而與該兩延伸耳部相樞設結合的制動臂，該下連接座與該連動組件及該制動組件相結合且設有一本體、一推抵塊及一緩衝墊，該本體設有兩結合凸耳、一置放槽及一凹槽，該推抵塊可擺動地與該本體相結合，該推抵塊的前端設於置放槽內，且兩連動臂與該本體及該推抵塊相結合，該推抵塊於頂部凹設有一擺動槽，使該制動臂的底端設於該擺動槽內且與該推抵塊相結合，該緩衝墊設於該凹槽內且與該推抵塊相抵靠，藉以提供一結構精簡、方便組裝使用且節省成本的義肢膝關節。
