Microwave is a very important medium in modern life, there are virus applications of microstrip sensors such as in communications, spacecrafts, satellite, industry and agriculture fields. In this book, we successfully developed linear and circular (ring) microstrip sensors for quick and accurate determination of moisture content in hevea rubber latex. The work combines two separate fields of study which includes the development of microstrip sensors and moisture measurement of fresh hevea rubber latex. The detailed design, analysis, construction and testing of the microstrip sensors have been presented in this book, where it was clearly found that the microstrip linear path sensor were more sensitive compared to microstrip circular ring sensor with 13.698 %/dB and 3.0697 %/dB, respectively. This book presents the details of a comparison analysis of linear and circular microstrip methods for the determination of moisture content in hevea rubber latex.