The high demand is applied to the infrared detectors for resources remote sensing,such as high detectivity, high reliability, low power, multi-waveband, good uniformity of detectivity. The assembly usually consists of filters, infrared detectors and pre-amplifiers. The main parameters of the assembly for remote sensing applications are discussed in this paper. Some problems are thought over in the assembly designing and testing. In detector applications, it is very important that specific meaning of assembly parameters and reasonable testing methods are very important.