Background: Partial obstruction of the small intestine causes obviously hypertrophy of smooth muscle cells which is a physiological response to the increased pressure in the lumen accompanied by motility disorder. Aims: To identify electric remodeling of hypertrophic smooth muscle cells in partial obstructed small intestine of mice. Methods: Partial intestinal obstruction was induced by surgically placing a ring of silicon tube on the distal portion of the ileum in male imprinting control region (ICR) mice. Patch-clamp and intracellular microelectrode recordings methods were used to identify the possible electric remodeling in hypertrophic smooth muscle. Alterations of channel protein expression and phosphorylation level were examined by westernblot, immunofluorescence and immunoprecipitation methods. Results: Partial obstruction induced smooth muscle hypertrophy in the proximally located intestine after obstruction 14 days and slow waves of intestinal smooth muscles in the dilated region were significantly suppressed, for example, their amplitude and frequency were reduced, whilst the resting membrane potentials were depolarized compared with normal and sham animals. The current density of voltage dependent potassium channel (Kv) was significantly decreased in the hypertrophic smooth muscle cells and changed voltage sensitivity of Kv activation. The sensitivity of Kv currents (IKv) to 4-AP, a Kv blocker, increased significantly but not to TEA, a nonselective potassium channel blocker. However, the Kv4.3 and Kv2.2 expressions were up-regulated in the hypertrophic cell membrane as well as serine and threonine phosphorylation levels of Kv4.3 and Kv2.2 were significantly increased in the hypertrophic smooth muscle cells. Conclusions: Partial intestinal obstruction-induced smooth muscle hypertrophy accompanyed electric remodeling. The enhanced phosphorylations of serine and threonine in Kv4.3 and Kv2.2 may contribute to membrane potential depolarization of hypertrophic smooth muscle cells. Key words Voltage dependent potassium channel; small intestine; partial obstruction; smooth muscle hypertrophy; resting membrane potential.