The purpose of this study was to estimate the standard of normal spleen size and its variations in relation to age, body weight(BW) and 1st lumbar vertebra($L_1$) length using radiographs. The Maximum transverse length (MTL) and maximum vertical length(MVL) of the spleen were obtained from ventrodorsal abdominal radiographs of 134 dogs which underwent radiography for indications unrelated to splenic disease. Splenic size did not significantly correlated with the age. MTL and MVL increased with BW according to the nonlinear correlation. Also, MTL and MVL increased with $L_1$ length according to the linear correlation.