An approximate theory of circular chlindrical shells under arbitrary load is derived on the basis of Vlasov"s semimembrane theory. With this approximate theory concrete cylindrical shells subjected to wind loading is analized and its accuracy is investigated with the results of Donnell"s equation. In this study the foollowing results are abtained : (1) The expression of .kappa.$\_$2/=.part.$^$2/.omega./.part. s$^$2/ for the change of curvature gives much simplicated closed form colution. (2) This approximate theory is to be applicable with sufficient accuracy in the stress analysis of concrete cylindreical shells which the ratio L/D is equal or greater than three.