This experiment was carried out to find the method for mass production by artifical cultivition and to analyze the components of Paecilomyces japonica according to several media. Time of inoculation of the Paecilomyces japonica using silkworm was on first day of five molting and infection rate was 72.0%. Optium medium for mass production of the Paecilomyces japonica was known effective for increasing dry weight and fruitbody at brown rice 80g plus pupa powder 20g. Dry weight of Paecilomyces japonica using fungus of silkworm was 1.2g including pupa and length of fruitbody was appeared 3.0cm to 3.5cm. Content of $eta$ - glucan was very high as 40.5% at inoculation on the first day of the five molting while 16.4% at brown rice, 20.7% at pupa, 23.1% at brown rice plus pupa powder, and 28.7% at pine sawdust plus wheat bran. Mycelium was poor and pinkly conidiospore was formed on media of centipede, maggot and powder of silkworm.