The developmental time of immature stages of Paromius exiguus (Distant) was studied at eight different constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5 and 35°C) with a photoperiod of 14:10 (L:D) h on two host plants, Imperata cylinderica and Calamagrostis epigeios. On both host plants, the developmental time decreased with increasing temperatures. A significant difference in the developmental times was observed between two host plants for each nymphal stage and for the total nymphal stage as well. For completion of the total nymphal stage, the development time at 17.5 and 35°C were 69.6 and 16.6 days on I. cylinderica and 38.6 and 13.8 days on C. epigeios, respectively. The relationship between developmental rate and temperature was fitted to a linear regression model and the six nonlinear models (Lactin 1, Lactin 2, Briere 1, Briere 2, Logan 6 and Taylor). Except for the Taylor model, all of the five nonlinear models fitted the data for the total nymphal stage of the current study well, according to the high r2 value, on both host plants. The distribution of completion of each development stage was well described by the two-parameter Weibull function.