Abstract: This paper focused on the desiccation cracking problem of grass-covered lateritic soil. Three commonly used herbaceous plants in highway slope protection(i.e.,Lolium perenne,Cynodon dactylon and Trifolium repens) were selected for study. Laboratory drying tests were conducted to examine the influences of drying duration,root type,plant spacing,specimen size,plant stems and leaves,and season on the desiccation cracking behavior of grass-covered lateritic soil. The results show that with an increase in drying duration,the external crack length of grass-covered lateritic soil gradually increases and then tends to be stable. However,the internal crack parameters such as crack rate,crack length and average crack width remain increasing. The mitigation effect of plants on soil cracks is closely related to the root type. Cynodon dactylon has the best mitigation capacity on desiccation cracks due to its inverted triangular fibrous root system,while Trifolium repens has the worst mitigation capacity on cracks due to its taproot system. With a decrease in plant spacing,the internal crack rate of lateritic soil decreases first and then increases. The later increase in crack rate is mainly caused by the increasing gaps between roots and soil as well as the increasing root suction. The crack rate reaches the minimum when the spacing of Lolium perenne is 4 cm,which indicates that the distribution of grass roots is rational and the crack-mitigation effect is the best in this case. The specimen size affects the crack rate and length,but has less effect on the crack average width. The influence of plant stems and leaves on the development of desiccation cracks depends on the reducing soil water evaporation due to leaves' covering effect and the water loss acceleration due to transpiration. The cracking behavior of lateritic soil is greatly affected by seasons. In winter,the soil mainly shows integral shrinkage while less desiccation cracks. The research results could provide references for vegetation-based protection design of cracked lateritic soil cut slopes.