Abstract: The article challenges the literature conceraed on What's the proper value for build coefficient K₁ in calculation of floating-roof tank anti-wind stability. Through analysis of the principle concerned and the load distribution obtained by tunnel test on a floating-roof tank model, it concludes that taking 1.5 for K₁ value is not proper. It is recommended to take no more than 1.0 at most. For smaller tanks, it would by all right to take 0.7. It ends by pointing out the fact that such a value taken in this way is approximate to that taken abroad.