Power-counting and renormalizability in Lifshitz scalar theory

We study the renormalizability in theories of a self-interacting Lifshitz scalar field. We show that although the statement of power-counting is true at one-loop order, in generic cases where the scalar field is dimensionless, an infinite number of counterterms are involved in the renormalization procedure. This problem can be avoided by imposing symmetries, the shift symmetry in the present paper, which allow only a finite number of counterterms to appear. The symmetry requirements might have important implications for the construction of matter field sectors in the Hořava-Lifshitz gravity.