Abstract：The third member of the lower Cambrian Balang Formation at Yangjiaping, Shimen, Hunan Province consists mainly of dark-gray, gray-green laminated to thinly bedded silt-bearing hydromica mudstones and muddy siltstones intercalated with lenticular and striped siltstones, whose sedimentary environment was a slope environment. Cross laminations are well developed in lenticular and striped siltstones of the middle and upper Parts of the third member, whose laminae are inclined not only bi-directionally up- and down the slope, but also uni-directionally which correspond to up-or down-slope directions. The characteristics indicated that lenticular and striped siltstones should not be contourites or turbidites, but should be formed by alternating up- and down-slope currents produced by internal waves and internal tides. This is the first example of internal-wave and internal-tide deposits found in the Cambrian.