Abstract: In this paper, the data memory technology of embedded USB host computer interface was described, which can meet the demand that a large amount of information stores in the greenhouse environment monitoring and controlling system. This technology regarded 51 serial single chip computers as the key device embedded with USB interface chip SL811HS with master and slave work patterns. According to USB1.1 protocol and systematical file of USB flash disk, USB driver and data store application program was worked out. Then the storage of large capacity information in the USB flash disk and read/write operation of the flash disks with capacity of 64M or 128M were realized by the data memory technology integrated in the greenhouse environmental monitoring and controlling system developed independently. This technology can also be used to control the USB printer and USB scanner by little modification of driver and data storage application program. With characteristics such as low costs, strong universal ability, good reliability, easy to operate and high dependability, this technology can be easily integrated into different monitoring and controlling systems to meet the need of different users.