摘要ABSTRACT Objective:To study the number of leptospirosis cases in relations to the seasonal pattern, and its association with climate factors.Methods:Time series analysis was used to study the time variations in the number of leptospirosis cases.TheAutoregressiveIntegratedMovingAverage (ARIMA) model was used in data curve fitting and predicting the next leptospirosis cases. Results:We found that the amount of rainfall was correlated to leptospirosis cases in both regions of interest, namely the northern and northeastern region ofThailand, while the temperature played a role in the northeastern region only.The use of multivariateARIMA(ARIMAX) model showed that factoring in rainfall(with an8 months lag) yields the best model for the northern region while the model, which factors in rainfall(with a10 months lag) and temperature(with an8 months lag) was the best for the northeastern region.Conclusions:The models are able to show the trend in leptospirosis cases and closely fit the recorded data in both regions.The models can also be used to predict the next seasonal peak quite accurately.