Scale is the highlight of the eco-environment, Characteristic scale is the optimized spatial measurement size to identify the heterogeneity of landscape. The study selects 6 ecological sampling lines including three latitudinal lines and three longitude lines as the research area in Fuzhou city. By use of Landsat TM image, the study gets the information of the Normalized vegetation index（NDVI）for 6 sampling lines. Then wavelet is applied as the multi-scale analysis tool, the regional NDVI information can be decomposed into a scale series：21×900 m2,22×900 m2…28×900 m2. After calculating the variance coefficient and entropy of wavelet detailed information in different scales, the results show that the corresponding scales to the maximum of wavelet variance and entropy may make up the domain characteristic scale of NDVI. By the way, NDVI domain characteristic scale for every ecological lines is clearly demonstrated. Finally, the study shows that the domain characteristic scale of ecological lines in different latitudes is between 24×900m2…26×900m2, latitude plays little role on the NDVI characteristic scale while the landscape diversity or complexity and disturbance from human activity play important roles for the NDVI characteristic scale size in ecological lines. For ecological lines with different longitudes, the domain characteristic scale is 25×900m2…27×900m2. From west to east, the characteristic scale increases gradually, it accords with the decreasing gradients of DEM, slope and relief. Furthermore, the study promotes that the regional NDVI domain characteristic scale in Fuzhou is under the control of the local NNE-SSW geological structure direction which impacts on the change of local characteristic scales in the spatial range of 21×900m2…23×900m2.