Room temperature phosphorescence (RTP) materials show potential applications in information security and optoelectronic devices,but it is still a challenge to achieve RTP in organic materials under water ambient due to the unstable property of triplet states.Herein,water-induced RTP has been demonstrated in the organic microrod (OMR).Noting that the RTP intensity of the as-prepared OMR is greatly enhanced when water is introduced,and the reason for the enhancement can be attributed to the formation of hydrogenbonded networks inside the OMR.The hydrogen-bonded networks can confine the molecular motion effectively,leading to the stability of triplet states;thus the lifetime of the OMR can reach 1.64 s after introducing water.By virtue of the long lifetime of the OMR in the presence of water,multilevel data encryption based on the OMR has been demonstrated.