Abstract: The phenology of hawthorn flower has been examined during 1388 and 1389. The begging and ending date of its flowering, the duration of flowers burst in a corymb, the percent of corymbs with secondary corymbs, the average of flower numbers in each corymb and the average of flower stamen and style were all evaluated. In addition, the ovum Longevity, the pollination striking period of hawthorn were examined with sampling of flowers (two, three, seven and nine days after pollination) and microscopic observations of samples took place. In this study, the ovum Longevity and the pollination period of Hawthorn are respectively 9 and 4 days. It is showed that after pollination, the pollen tube would start growing downward to the bottom of style. The Transparency and brightness of ovum would be the sign of oldness and ending of its action. In order to specify the growth of Hawthorn fruits and drawing the growth curve, the fruit diameter were measured with calliper during the specified times of 3, 6.9,12, and 17 weeks after the flowering completion. The growth curves of flowers were drawn and in contrary to the fruits with seeds, it was like stone fruits and in the form of double sigmoid. The highest level of fruit growth has been observed through the time of three to six weeks after the end of flowering.