Abstract:By investigating the utilization of machines in log production line of log yard in Yichun forest region, the authores make researches on the production levels of the log production lines and the machine utilization coefficents in every working procedure.Taking the least loss of machine utilization in working procedure as a goal, the authors have studied the 7 kinds of machine combination types and 17 combination plans. The authores have also analized the log production line (Lmi Si-Y) combined with door type crane and conveyer, and have selected the best combination plan.