【Background】The apple snail, Pomacea canaliculata Lamark is an exotic invasive pest in China. The study on the relationship between morphological characteristics and body mass quantified by correlation analysis and path analysis was few. 【Method】P.canaliculata in 7 regions of Guangdong Province were collected by random with huge sex ratio, four morphometric traits (shell height, shell width, mouth width and whorl height), and body mass were measured. The relationship between morphological characteristics and body mass was quantified by correlation analysis, path analysis and multiple regression analysis. No significant morphological characteristics in multiple regression equation were deleted, thereby the most corrected variables with body mass were selected from different regions. 【Result】The results showed that shell height, and width, had the hightest relationship with body mass, significant at all locations, except for Huizhou City. Shell mouth width and shell height had the strongest effect on body mass. 【Conclusion and significance】This study will have important implications on apple snails in terms of morphological identification, classification and damage forecasting in different habitats.