In direct drive inertial confinement fusion， surface perturbations seeded by imprint from laser intensity variations play an important role in Rayleigh-Taylor（RT） growth. Laser imprinting and consequent RT growth in planar CH targets driven by different pulse shapes have been investigated. The experimental results reveal that the range of density modulation induced by laser imprinting is larger when the driving laser has lower foot intensity and rises more slowly. Enhancing the pre-pulse intensity can restrain the effect of laser imprinting notablely.