Moisture status in the crop is closely related to various physiological activities of the crop. If we can measure the moisture status in the crop in real time, we can understand the photosynthetic activity, which is an important physiological activity for growing crops, and the movement of the product from photosynthesis. Therefore, we verified it is possible to measure water content of crop leaves nondestructively using invasive method and non-invasive method. As a non-invasive measurement method, we tried to nondestructively measure water content in crop leaves using a hyperspectral camera. In this experiment, the hyperspectral camera (SIS-I, Eva Japan) was adopted. As an invasive measurement method, we developed a small sensor with a light receiving part with InGaAs photodiode mounted and a light projecting part with LED with peak wavelength at 1450 nm (Hamamatsu Photonics K.K., Japan). In each measurement method, tomatoes were used as test samples. Thereafter, the fresh weight and dry weight of the leaves were measured to calculate the water content and compared with the sensor data. As a results, the estimation accuracy by the hyperspectral camera was a determination coefficient (R2) of 0.74. In case of development small sensor, the coefficient of determination (R2) was 0.58. In addition, it was confirmed that the water content of tomato leaves decreased from the plant foot treatment to the plant apex. As a results, we obtained a possibility for measuring water content in crop leaves by non-destructive measurement method. And also, we obtained a possibility for grasp the crop state in real time by measuring the water content in the crop at each height from the ground.