This research was conducted at the company PT. Perkebunan Nusantara III Medan, the purpose of this study is to analyze the ratio of activity to working capital with liquidity as a moderating variable at PT. Nusantara III Plantation Medan 2015-2017 period. The method in this study is a quantitative method using financial statements and the sample of this research is 36 samples, namely from the 2015-2017 period and taken with documentation techniques. The independent variables in this study for the activity ratio are measured by Receivable Turnover and Inventory Turniver, the liquidity variable is measured by the Current Ratio and Working Capital is measured by the Debt to Equity Ratio. This study uses secondary data and research hypotheses using Partial Least Square analysis using SmartPls software with the result that only Inventory Turnover has a positive effect on Working Capital while Receivable Turnover has no effect on Working Capital. Liquidity also cannot be a moderating variable of the effect of Receivable Turnover and Inventory Turnover on Working Capital.