Purpose : To analyze high-resolution CT findings(HRCT) of pulmonary lymphangitic carcinomtosis(PLC) and tocorrelation the HRCT findings with the results of pulmonary function test(PFT). Materials and Methods : In Twenty eight patients with radiologically and clinically proved PLC, we retrospectively reviewed HRCT scans and PFT(N=12). PLC was classified by extent and distribution of metastatic nodules and interstitial thickenings on HRCT and the findings were correlated with the results of PFT and impairment of PFT according to the degree of FEV1(forced expiratory volume in one second). Results : On the basis of distribution of PLC, HRCT findings showed 20 cases of peripheral type, 3 cases of central type, and 5 cases of mixed type. In the patients with PFT diffuse type was 10 cases and localized type was 2 cases In diffuse types, the restrictive pattern occurred in 7 cases(p<0.05) and in localized types, restrictive pattern occurred in 2 cases. Marked impairment of vital capacity was shown as restrictive pattern in 7 cases all of which were diffuse type and were consisted of peripheral type in 4 cases and mixed type in 3 cases. Conclusion : HRCT findings of lymphangitic carcinomatosis correlated well the type and degree of impairment of PFT. Especially, in diffuse type of lymphangitic carcinomatosis, the result ofpulmonary function test were prominent restrictive patterns. Marked impairment of pulmonary function occurred in patients with diffuse type and types with peripheral interstitial thickening(periphral and mixed types).