  In this paper, we introduce the concept of quasi Yamabe gradient solitons,
which generalizes the concept of Yamabe gradient solitons. By using some ideas
in [7,8], we prove that $n$-dimensional $(n\geq3)$ complete quasi Yamabe
gradient solitons with vanishing Weyl curvature tensor and positive sectional
curvature must be rotationally symmetric. We also prove that any compact quasi
Yamabe gradient solitons are of constant scalar curvature.
