The study was made on the growth and development of tobacco leaves by intensive observation in leaf growing stages of variety K326. The result showed that the appearance rate of leaves was slow at the early stage and fast at the late stage. 5~6 days were needed to have a new leaf for the early leaves (4~8), only 2~3 days or 1~2 days were needed for middle leaves (5~18) and late leaves (19~34) respectively. The ratio of leaf length to width was between 1.45 to 2.63, lower for earlier and later leaves and higher for middle ones. All leaves had similar expansion rule for leaf length, width and leaf area. They fitted well with the Richards equation with good level of fit (R2), so their growth could be described using the Richards equation. On average, 16.4 days was needed to reach the first half of the final leaf area. The maximal growth rate of leaf area was about 17.44 days after first appearance. The practical leaf growing period (reaching 99% of the potential leaf area) was about 36.8 days. Tobacco leaf maintained a long period of continuous growth after a fast growing stage, especially for those plants which were topped. The leaf increased its area slowly, rapidly, and slowly again with the increase of leaf position. This process could be fitted with Richards equation as well.