Hu Chien-Shan (1911—2004) was an educator and expert in vibration and engineering mechanics who studied cosmic ray showers under P. M. S. Blackett in London from 1934 to 1937. He participated in international experiments on cosmic rays，and collaborated with Soviet physicists in observing cosmic ray showers at 4000m above sea-level on Mt. Kazbek in the Caucasus. He was one of the pioneer Chinese physicists to study cosmic rays，but later devoted himself to the study of mechanical vibration due to the lack of equipment. To commemorate the centennial anniversary of Hu Chien-Shan’s birth in 1911 and that of the discovery of cosmic rays in 1912，this paper reviews the research on cosmic rays that Hu performed in the 1930s，based on his doctoral thesis and two articles in the Proc. of the Royal Soc. of London. We hope to provide the reader with some details of the research of physicists in this field during that historical period.