Abstract: In the research on the soil adhesion,　it is necessary to measure the soil surface moisture, so that a near infrared moisture analyzer for soil surface was developed, which is based on the near infrared specific absorptive principle of water. The analyzer possesses many advantages such as high pricision, short measuring time, without disturbing the measured soil system and can be used on line.　Its standard measuring error is 0.13%. The principle and effection of correlation filter are also discussed in the paper.　The analyzer can be also used to measure the moisture of many substances,　such as tobacco, paper, flour and tea.