Based on comprehensive study of cores and various data,the author considered that the sandstones and oolitic limestones in the Middle and Upper Ordovician of Well TZ32 in the Tarim Basin were mainly origin of internaltide deposits. The thickness of Middle and Upper Ordovician drilled in Well TZ32 is 1 462 m and mainly composes of alternating beds of darkgray mudstones and/or shales and gray sandstones and/or siltstones interbedded with minor limestones,in which darkgray mudstones and/or shales are the most. Sandstones and siltstones are mainly concentrated in the upper and lower part. Oolitic limestones are rare and interbedded in darkgray mudstones and/or shales. These sandstones and oolitic limestones can form beds alone,but more commonly,form thin alternate beds with drakgray mudstones and/or shales in which flaser,wavy and lenticular bedding are welldeveloped,and cross bedding and bidirectional cross laminations are also welldeveloped. According to the sedimentary background and the characteristics of lithology and sedimentary structure combination,these sandstones and oolitic limestones are explained as the products of internaltide deposits on deep water slope. These internaltide deposits can be classified into four basic types according to their features,i.e.,bidirectional crosslaminated finegrained sandstone,unidirectional crossbedded and bidirectional crosslaminated mediumgrained to finegrained sandstone,rhythmic thin alternating beds of sandstone and mudstone,and oolitic limestone. These internaltide deposits possessed five types of vertical successions and formed rhythmic deposit combinations with cyclicity in the vertical section.