Purpose: The purpose of this study was to investigate electromyographic (EMG) activity of deep and superficial trunk muscles during trunk stabilization exercises with and without stabilization maneuvers. Methods: The relative muscle activity ratios and local muscle activities of 25 healthy males were measured using the 8 channel surface EMG system (Myosystem 1400A, Noraxon Inc., U.S.A). The surface EMG activities were tested during performing abdominal hollowing maneuver (AHM), abdominal bracing maneuver (ABM) and no stabilization maneuver (NSM) in random order. Data were analyzed using $1{ imes}3$ repeated measures ANOVA. Results: During bridging exercises, the EMG activity ratio of transverse abdominis/internal oblique abdominis relative to rectus abdominis was significantly lower in NSM than in AHM and ABM. During bridging and kneeling exercises, the EMG activity ratio of multifidus relative to erector spinae was significantly higher in AHM than in NSM. Conclusion: The AHM can be clinically used by the physical therapist to activate selectively the trunk muscles when designing selective training programs for patients.