The relationship between body length and biomass (dry weight) was investigated for nineteen taxa of terres trail arthropods and for the combined sample that included all insect taxa. The specimens were collected from forests of Bicholim taluk of Goa. Four models were evaluated, a linear function, a logarithmic function, a power function and an exponential function. The linear function best describes dry weights in the order Isopoda of class Crustacea and dictyopteran, coleopteran larvae of class Insecta. The logarithmic function fits well for only one group namely Opiliones of class Arachnida. The power functions fits best for Scutigeromorpha and Scolopendromorpha of class Chilopoda, Araneae of class Arachnida, Collembola, Thysanura, Orthoptera, Hemiptera, Homoptera, coleopteran adults, Diptera, lepidopteran adults and Hymenoptera of class Insecta and the combined data on adult insects. An exponential function fits well for the dermapteran and lepidopteran larvae of class Insecta. The usefulness of these estimates of Arthropod biomass in community ecology is discussed.