Environmental conditions, such as temperature and humidity can influence the adhesion forces and microtribological properties of microparts. To have a good understanding of microassembly, it is essential to study the influences of environmental conditions to microassembly process and system. This paper presents our research in environment controlled microassembly, including an environment controlled microassembly system and early results of the influences of environmental parameters on microassembly and pick-and-place operations. The environment controlled microassembly station can control the environmental conditions including temperature and humidity in a closed chamber where microassembly is carried out. The temperature can be controlled in the range of 10-40/spl deg/C and relative humidity of 5-80% RH. Experimental results of the influences of environmental conditions on a piezoelectric bender and piezo-ultrasonic stage are reported, as well as errors of pick-and-place operation. The experimental results show that both temperature and humidity can influence the performance and errors.