Abstract:In order to make better use of the data from Lightning Location Systems (LLS) to calculate the number of lightning days and lightning parameters, by means of the conventionally observed lightning day data from 49 Stations over the central Yunnan Province from 1987 to 2006 and the lighting location data from 2005 to 2006, the grid method for calculating lightning days and lightning parameters automatically is presented on the basis of comparing the observed and LLS data. By means of the grid method, the area division is more detailed and reasonable with a satisfactory comparability between calculated and conventional lightning day data. The longrange lightning day data are needed as sources for determining the size of grids, and the calculated result with the 0.175°×0.175° grid is chosen for annual mean lightning days and 0.3°×0.3° for maximum lightning days in the central Yunnan Province. The results of lightning parameters with the grid method show that there are obvious local variations in lightning days and lightning density, and the density of ground lighting and the strength of lighting have an inverse proportional relationship, which provides theoretical foundations for the engineering design of lightning protection, as well as the assessment and causal analysis of Lightning Disasters.