Larvae of the Chinese mitten crab Eriocheir sinensis were reared in the laboratory under 25 different combinations of constant temperature (6 to 18 degree C) and salinity (10 to 32 ppt S). Different schedules of changing salinity were tested only in the final larval stage, the megalopa. Pelagic larval development comprises a total of 5 zoeal stages and 1 megalopa. An additional (stage VI) zoea and in one case an additional megalopa (transitional to the juvenile) were occasionally observed under unfavourable conditions with low salinity ( less than or equal to 15 ppt S). Successful development from hatching to metamorphosis occurred only at temperatures greater than or equal to 12 degree C. With increasing temperature, both overall survival and range of salinity tolerance increased, whereas development duration decreased exponentially. Regression equations describing this relationship are given for different larval stages and salinities.