This study has continuously measured the Leq (10min) at the outskirt of the Kaohsiung Refinery of China Petroleum Company for 24 hours. The measured values are used to calculate the correlation coefficients between one Leq (10min) and Leq (1 hr), also between two Leq (10min) and Leq (1hr). The result shows that the correlation coefficient are almost above 0.9 indicating they are highly correlated. So it can be inferred that for the sake of reducing power, time and cost, the short-term measured value can substitute the long-term measured value of noise when continuously measure several locations in a close distance within 24 hours.