In order to configure wireless sensor networks system and node deployment in greenhouse, this paper researched propagation characteristics of 2.4 GHz wireless channel at different directions and heights in greenhouse of green peppers. Received signal strength and packet loss numbers were investigated by field testing measurements at three directions and two heights. Regression analysis results showed that the radio channel propagation characteristics in different directions and heights of green peppers accorded with logarithm distance path loss model, and the fitting correlation coefficients between computational values and measurement values were between 0.900 7 and 0.947 3. Different heights of sensor nodes in the green peppers determined the radio wave propagation characteristics. Besides, validation results showed that it was the best to deploy the sensor nodes antennas at the top of green peppers canopy or above of it in greenhouse. This research can provide technical support for WSN application in greenhouse.