Measuring snow wetness and snow density is essential for many applications in snow hydrology like avalanche warning, flood prediction, optimization of hydro power generation and investigations of glacier melting due to global warming and climate change. So far the snow parameter sensors were not suited for long time continuous measurements when disturbing melting processes around the sensor occur. In many respect the performance moreover suffered from their small measurement volume which is not adequate to achieve representative values for natural snow covers with large spatial variability. Therefore two new sensor have been developed. A light-weight sensor has been designed to position on a snow layer with minimal influence on the snow. This sensor with length 0.3 m is constructed from an aluminum tube of 3 mm diameter. It is convenient for continuous time domain measurement with regard to spatial and temporal variability of snow wetness or density. The other new sensor has a large measurement volume and the capability of monitoring the whole snow cover cycle. It consists of a flat band cable as TDR transmission line up to about 100 m long which is enclosed by snow fall. Time domain measurements or time domain measurements in a combination with low frequency measurements are suited for the determination of both snow wetness and snow density. Besides integral measurements along the flat band cable the possibility of reconstructing vertical snow parameter profiles with sloping transmission lines has also been investigated. Several measurement campaigns demonstrate, on the basis of the measured results, the successful practical application of the methods and sensors developed in this work.