In the geological teaching and geological photographic processes,the authors foundin 1988 phenomena similar to groove cast and flute cast at the bottom surface of sandstone deposited in shallow water, which are different from examples of groove cast andflute cast abroad cited in textbooks of China on sedimentary petrology in two aspects:(1) the groove cast observed is current scour cast rather than tool impression-scoringcast,(2) sediments underlying the observed groove cast and flute cast are arenaceousinstead of argillaceous. The discovery of such phenomena is a supplement and improve-ment to the phenomena of groove cast and flute cast,and is hence of great significancein finding out the origin of groove cast and flute cast as well as filling in the gaps ingroove cast and flute cast examples of China in textbooks of sedimentary petrology.