Abstract: The landscape quality of natural scenic forest mainly made of secondary forest was in a state of medium or low. The main basis of adjustment and transformation was the result of quality evaluation of in-forest landscape. A secondary scenic forest at Corn-growing Ditch Forest Park's in Jilin City, Jilin Province was taken as an example in this study. The beauty degree was objective target and the Scenic Beauty Estimation(SBE)method was adopted in this study. Main factors affecting the landscape quality of the forest were determined through correlation analysis, ANOVA analysis, regression analysis and cluster analysis. At the same time, a prediction model of quality evaluation was established, and the types of landscape quality were devided. The results showed that the tree form(X₄), naturalness degree(X₁₇), perspective distance(X₁₆)and the shrub height(X₈)were the main indicators that influenced on the landscape quality of secondary forest. The beauty degree model was built: M_SBE=-128.391+15.63X₄-3.615X₈+20.379X₁₆+17.933X₁₇. With the improvement of tree form, naturalness degree and perspective distance's scores, the beauty degree improved significantly(P<0.05), and when the height of the shrub got higher, the beauty degree's level reduced significantly(P<0.05). According to the results of cluster analysis, the forest landscape was divided into high, medium and low beauty degree of landscape. On the basis of three quality types of the study objects, the forest stand transformation approach were suggested, such as structure adjust, naturalness degree enhancement, forest form optimization, proper shrub's density and height control.