Polyploidy is an important evolution process for the creation of new species. Up to 70% of angiosperms are reported that as polyploids. Tetraploids development in watermelon is the first most step in the seedless fruit development. In this study, the colchicine was used to generate the tetraploid watermelons. The chloroplast counting methodology was adopted to segregate tetraploids. Among the 63 plants treated, one plant showed 11- 14 chloroplasts in the guard cells. Chimeral stomatal guard cells pertaining to the number of chloroplasts also identified in this investigation.