The standard of chair and desk is decided to design a science laboratory which would help students giving the chance to show their ability and participating spontaneously. The standard is come by the middle school students physical size of the 1986 national physical standard and they are classified into large, medium and small size. The size of laboratory is determined by the size of desk. the distance between desks and the number of students accommodated. By the middle school students physical standard, the heights of chair are 32, 34, 37cm and the widths of chair are 35, 37, 40cm. The desks heights are 53, 58, 63cm and the size is $110{ imes}160cm$. The distance between rear and front of desk is 120cm and the left and right side of desk is 150cm. When 24, 36, 60 students are accommodated in laboratory, the size of laboratories are $9.6{ imes}10.5m$, $12.7{ imes}10.5m$ and $18.8{ imes}10.5m$ respectively.