Spider is one species of the most spinning silk arthropods. Currently there are 8 kinds of silk glands, each with different biological functions, which used for some behavior activities of weaving nets, predation, escape, dispersal, woven eggs etc. Spider silk is a natural animal protein fiber, the result of 400 million years evolution of the spider, and it is also designed for the survival and reproduction of the spider. Adaptation and evolution of spider silk make itself have a variety of biological functions. But spider is not only spinning arthropod. Besides animal of Arachnids, there are many other arthropods, such as animal of Insecta and Myriapoda, have silk glands which can spin one or more kinds of silk protein fiber. Compared with insect, this paper will summarize the origin and types of spider silk gland, the composition,structure and varieties of spider silk fiber and their biological functions.