A nozzle for producing microparticles includes a nozzle body having an oscillating device and an amplifying portion connected to the oscillating device and located between first and second ends of the nozzle body. A through-hole extends from the first end through the amplifying portion and the second end. A tube assembly is mounted in the through-hole and includes first and second tubes between which a first fluid passageway is defined. A second fluid passageway is defined in the second tube. Two ends of the first tube respectively form a first filling port and a plurality of first outlet ports both of which intercommunicate with the first fluid passageway. Two ends of the second tube respectively form a second filling port and a second outlet port both of which intercommunicate with the second fluid passageway. A formation space is defined between the second outlet port and the first outlet ports.