English translation of a Russian technical study of silk and woolen textiles excavated by P. K. Kozlov's 1924-25 expedition from the Noin-Ula burial mounds in Mongolia. It describes the laboratory methods used (microscopy, chemical and dye analysis, photo-analysis) and gives sample-by-sample data on fibre, thread thickness, twist, count, tensile strength and elasticity, and weave. It also covers a large applied-work carpet (No. 14568) with tapestry-weave wool ground, felt appliqué, cords and stitching, plus analysis of woolen fabrics from Mound No. 6. Plates reproduce photographs, micrographs and cross-section diagrams of the fabrics.