Abstract: Impact of sandstorm hazard on cotton seedling growth and construction of quantitative indicators have important guiding significance for evaluating impact of sandstorm hazard on cotton yield． Through sand simulation experiments of different wind speeds, directions and durations, damage degree of sandstorm hazard to cotton growth was studied, and indicators of sandstorm hazard in cotton seedling stage（one true leaf to five true leaves）were obtained． Results showed that, from one true leaf to three true leaves, ability of cotton seedlings to resist sandstorm hazard increased with progress of growth, and resistance of cotton seedlings to sandstorm hazard at seedling stage changed abruptly at five true leaf stage． Effect of sandstorm hazard on cotton seedling stage divided into three stages, 8～14 m/s was affected growth stage, 14～17 m/s was severely affected stage, and more than 17 m/s was damaged stage． In actual production process, appropriate preventive measures for sandstorm weather could be taken according to specific weather forecast and combined with sandstorm hazard indicators at cotton seedling stage．