The object of the present invention is to provide a nozzle gate opening and closing timing adjusting mechanism used for multiple gate injection molding machine. And, a mechanism of the present invention is characterized that a nozzle gate opening and closing timing adjusting mechanism for use in a multiple gate injection molding machine having a plurality of resin injecting nozzles, each having disposed therein a gate pin that opens and closes a nozzle gate, the nozzle gates being opened by the gate pins when, in filling with a resin, a resin pressure exceeds a predetermined value and the nozzle gates being closed by the gate pins when the resin pressure falls below a predetermined value, the nozzle gate opening and closing timing adjusting mechanism comprising: timing pins, disposed at all or a portion of surfaces of an injection mold opposing the respective nozzle gates and advancing and retracting toward and from the nozzle gates; and opening and closing timings of the plurality of nozzle gates being adjusted by the nozzle gates being opened and closed by the timing pins directly or indirectly via the gate pins.