The conception of Bernard effect and cholesteric liquid crystal texture are introduced. The sample of cholesteric liquid crystal in planar texture is prepared

the texture change with temperature field by polarizing microscope is observed. The Bernard effect or pane grate effect under the cleaning temperature is appeared. The experimental phenomena show that the temperature field induced the liquid crystal molecule convection

the birefringence interference is occurred

and liquid crystal director distribution is periodical variation

so that the microcosmic Bernard effect pattern formed. The experimental phenomena wait for explanation rightly

and have some significance for liquid crystal physics basic research.