Haptic technique is a tactile feedback skill between humans and machine devices. How to deal with the compliantly controlled haptic interaction is essential. This paper proposes an impedance control design based on Luenberger observer for haptic linear servo motors. With the consideration of practical implementations, the Luenberger observer is substituted for tactile sensors to estimate the external force exerted by humans. The controlled motion looks like a spring-mass-damper system required by the desired haptic system and realized by the proposed impedance control. Simulation and experimental results are given to show that the dynamic behavior of the controlled linear servo motor is analog to a desired spring-mass-damper system.