The study was to investigat of varies cutting intervals of second cutting sweet grass in Phetchaburi soil series on growth characteristics, yields and chemical composition. The experiment was designed as randomized complete block design with 3 replications. The treatments were 3 cutting intervals as 45, 60 and 90 days with 3 replication. The result showed that increasing of age cutting grass effected to the clump weight, stalk weight, leaf width, leaf length, stalk height, total stalk height, internode length, leaf number and internode number were increased significantly (P<0.05). The fresh yield was significantly increased (P<0.05) of 3.33, 5.78 and 6.81 ton/rai with increase cutting intervals at 45, 60 and 90 days, respectively. The average chemical composition of the crude protein was 12.80, 9.96 and 8.55 percent significantly decreased (P<0.05) according to the cutting intervals at 45, 60 and 90 days. The fiber values ​​of NDF and ADF were increased with increase cutting intervals grass. The present study, it can be concluded that second cutting sweet grass with increasing of age cutting grass has the effect of increasing the buding regrowth, clump weight and fresh yield. Thus, the optimal cutting interval was at the range of 60-90 days with suitable yield and quality for use in animal husbandry. Therefore, the suitable of protein content, NDF and ADF level for used of microbial in rumen and good digest.