A completely new type of solid-state round travelling-wave laser was presented. The resonator consists of only two concave mirrors and one of them is coated on the curved surface of the laser material. Between the mirrors the laser beam travelled in a closed 3-dimensional loop. Oscillations of many kinds of round travelling-wave laser modes have been observed , and lasers pumped at two defferent points on the active material have been developed. The experimental results indicates that the novel laser has most simple structure and very stable output. Using this design, high-efficient laser, single-frequency laser and mode-locked laser with short cavity length can be developed.