Abstract: During the past two decades, Precambrian research, especially in the respect of the occurfence of microbial fossils in silicified rocks has been achieved. It is still in argument, however, at what time the origin of the eukaryote, one of the major events in biological evolution appeared according to the different criteria of the low, er eukaryotic organism fossils identified. The difference between prokaryotic and eukaryotic algal fossils in the cell size of structure and morphological colony and the model of their reproduction in biologic evolution is interpreted based on the knowledge about living lower organisms in this paper. Eight genera and eight species of eukaryotic algal fossils, including three genera and three species (Proto- cosmarium panduratum, Closteriopsis taihangensis and Phyllophycoma sinensis) newly descover ed in black stromatolitic chert from Gaoyuzhuang Formation, Lingqiu, Shanxi Province, China, which is about 1,400–1,600 My in age are described and named. All of these are characterized by the big cell size and complex structure of colony in which the cells have been divided into different function in physiology, and some of them produce endospore and autospore which are comparable with their mother cell or colony in morphology. According to the morphological characters of complex and diverse microfossils, it is assumed that the evolution of eukaryotic organisms had been achieved and even evolved up to a higher level at least before 1,600 million years.

Key words: Mid-Proterozoic era, North of Taihang Mountain, Eukaryotic Fossils