An apparatus for tightening and loosening a lace, comprising: a base, the base defining an accommodating space which communicates with an ambience by two lacing holes, wherein the base further comprises a plurality of base annular teeth; a lace tightening and loosening member pivotally mounted in the accommodating space and comprising an annular track and a first combining portion, wherein the annular track is corresponding to the two lacing holes; a releasing unit comprising a rotating knob and a shaft member; and an interlocking member being rotatably positioned in the accommodating space and comprising at least one elastic abutting arm and a second combining portion, wherein the at least one elastic abutting arm is correspondingly engageable with the base annular teeth; wherein the base further comprises at least one stopping member; the shaft member further includes a first positioning portion, a second positioning portion and a temporary sliding portion, the temporary sliding portion being disposed between the first positioning portion and the second positioning portion, the releasing unit being pivotally mounted in the accommodating space and the at least one stopping member being positioned in the first positioning portion or the second positioning portion, wherein the stopping member is switchable between the first positioning portion and the second positioning portion by passing over the temporary sliding portion by a preliminary force; and the interlocking member being further connected to the releasing unit, wherein the interlocking member and releasing unit are simultaneously movable in an upward or downward direction; wherein, when the stopping member is positioned by the second positioning portion, the releasing unit and the interlocking member are located at a lower second position, in which the second combining portion is correspondingly connected to the first combining portion and the position of the interlocking member in the accommodating space is corresponding to the position of the base annular teeth, such that the at least one elastic abutting arm is engaged with one of the base annular teeth and substantially stops the releasing unit from rotating in a loosening direction but does not substantially stop the releasing unit from rotating in a tightening direction; wherein, when the stopping member is positioned by the first positioning portion, the releasing unit and the interlocking member are located at an upper first position, in which the second combining portion is completely or partially separated from the first combining portion, and the position of the interlocking member in the accommodating space is not corresponding to the position of the base annular teeth. a base, the base defining an accommodating space which communicates with an ambience by two lacing holes, wherein the base further comprises a plurality of base annular teeth; a lace tightening and loosening member pivotally mounted in the accommodating space and comprising an annular track and a first combining portion, wherein the annular track is corresponding to the two lacing holes; a releasing unit comprising a rotating knob and a shaft member; and an interlocking member being rotatably positioned in the accommodating space and comprising at least one elastic abutting arm and a second combining portion, wherein the at least one elastic abutting arm is correspondingly engageable with the base annular teeth; wherein the base further comprises at least one stopping member; the shaft member further includes a first positioning portion, a second positioning portion and a temporary sliding portion, the temporary sliding portion being disposed between the first positioning portion and the second positioning portion, the releasing unit being pivotally mounted in the accommodating space and the at least one stopping member being positioned in the first positioning portion or the second positioning portion, wherein the stopping member is switchable between the first positioning portion and the second positioning portion by passing over the temporary sliding portion by a preliminary force; and the interlocking member being further connected to the releasing unit, wherein the interlocking member and releasing unit are simultaneously movable in an upward or downward direction; wherein, when the stopping member is positioned by the second positioning portion, the releasing unit and the interlocking member are located at a lower second position, in which the second combining portion is correspondingly connected to the first combining portion and the position of the interlocking member in the accommodating space is corresponding to the position of the base annular teeth, such that the at least one elastic abutting arm is engaged with one of the base annular teeth and substantially stops the releasing unit from rotating in a loosening direction but does not substantially stop the releasing unit from rotating in a tightening direction; wherein, when the stopping member is positioned by the first positioning portion, the releasing unit and the interlocking member are located at an upper first position, in which the second combining portion is completely or partially separated from the first combining portion, and the position of the interlocking member in the accommodating space is not corresponding to the position of the base annular teeth.