A lateral transient voltage suppressor for low-voltage applications. The suppressor includes an N-type heavily doped substrate and at least two clamp diode structures horizontally arranged in the N-type heavily doped substrate. Each clamp diode structure further includes a clamp well arranged in the N-type heavily doped substrate and having a first heavily doped area and a second heavily doped area. The first and second heavily doped areas respectively belong to opposite conductivity types. There is a plurality of deep isolation trenches arranged in the N-type heavily doped substrate and having a depth greater than depth of the clamp well. The deep isolation trenches can separate each clamp well. The present invention avoids the huge leakage current to be suitable for low-voltage application.